Methods for making polyfunctional organosiloxanes and compositions containing same

ABSTRACT

A polyfunctional organohydrogensiloxane is prepared using a boron containing Lewis acid as catalyst. The polyfunctional organohydrogensiloxane may be formulated into release coating compositions. Alternatively, the polyfunctional organohydrogensiloxane may be further functionalized with a curable group to form a clustered functional organosiloxane. The clustered functional organosiloxane may be formulated into thermal radical cure adhesive compositions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/783,229 filed 21 Dec. 2018 under 35 U.S.C. § 119 (e).U.S. Provisional Patent Application No. 62/783,229 is herebyincorporated by reference.

TECHNICAL FIELD

A method for making a polyfunctional organosiloxane is disclosed. Thepolyfunctional organosiloxane comprises a linear polydiorganosiloxanebackbone with cyclic siloxane endblockers. The polyfunctionalorganosiloxane is useful in curable compositions, e.g., as acrosslinker.

BACKGROUND

Methods for making polyfunctional organosiloxane crosslinkers havinglinear polydiorganosiloxane backbones with cyclic siloxane endblockershave been proposed using platinum catalyzed reaction of cyclicpolyorganohydrogensiloxanes with either vinyl terminatedpolydiorganosiloxanes or hydroxyl terminated polydiorganosiloxanes.These methods suffer from the drawbacks of requiring purification of thecyclic polyorganohydrogensiloxanes, which is costly. These methodsfurther suffer from the drawback of poor ability to control structureand molecular weight of the products.

SUMMARY

A method for preparing a polyfunctional organohydrogensiloxane using aboron containing Lewis acid as catalyst is disclosed. The method mayfurther comprise functionalizing the polyfunctionalorganohydrogensiloxane to form a clustered functional organosiloxane.The polyfunctional organohydrogensiloxane and the clustered functionalorganosiloxane are useful in curable compositions.

DETAILED DESCRIPTION OF THE INVENTION

The polyfunctional organohydrogensiloxane prepared by the methoddescribed herein comprises a linear polydiorganosiloxane backbone withcyclic SiH functional endblockers. The polyfunctionalorganohydrogensiloxane may be used as a crosslinker. The polyfunctionalorganohydrogensiloxane is useful in curable compositions, such asrelease coating compositions.

A method for preparing a product comprising the polyfunctionalorganohydrogensiloxane comprises the steps of:

1) combining starting materials comprisingA) a boron containing Lewis acid;B) a hydroxyl terminated polydiorganosiloxane of formula

where each subscript n is 2 to 2,000, and each R¹ is independentlyselected from the group consisting of monovalent hydrocarbon groups andmonovalent halogenated hydrocarbon groups; andC) a cyclic polyorganohydrogensiloxane of formula (RHSiO_(2/2))_(v),where subscript v is 3 to 12;and each R is an independently selected monovalent hydrocarbon group;thereby preparing the product comprising the polyfunctionalorganohydrogensiloxane and a by-product comprising H₂. The startingmaterials in step 1) may optionally further comprise D) a solvent.

The method may optionally further comprise one or more additional steps.The method may further comprise recovering the polyfunctionalorganohydrogensiloxane. The method may further comprise: 2) duringand/or after step 1), removing the H₂ generated during formation of thepolyfunctional organohydrogensiloxane and/or 3) neutralizing residualboron containing Lewis acid in the product. By-product H₂ may be removedby any convenient means, such as stripping and/or burning. Neutralizingmay be performed by adding E) a neutralizing agent to the product andthereafter filtering the product. Steps 2) and 3) may be performed inany order. If a particulate by-product is present, e.g., as a result ofneutralization, the method may further comprise 4) removing aparticulate such as alumina after neutralization by any convenientmeans, such as filtration.

One or more of the method steps may be performed at a temperature of 5°C. to 70° C., alternatively 5° C. to 65° C., alternatively 10° C. to 60°C., alternatively 15° C. to 50° C., alternatively 20° C. to 35° C.,alternatively 5° C. to 30° C., and alternatively 30° C. Alternatively,step 1) may be performed at the temperature of 5° C. to 70° C.,alternatively 5° C. to 65° C., alternatively 10° C. to 60° C.,alternatively 15° C. to 50° C., alternatively 20° C. to 35° C.,alternatively 5° C. to 30° C., and alternatively 30° C. Without wishingto be bound by theory, it is thought that performing the method,particularly step 1) at relatively low temperatures (e.g., 90° C. orless, alternatively 80° C. or less, alternatively 70° C. or less, andalternatively 50° C. or less) may provide improved reaction rate, yield,or both.

The starting materials used in step 1) of the method, alternativelysteps 1), 2), and 3) of the method, may be free of platinum group metalcatalysts. “Free of” as used herein includes none, alternatively anamount non-detectable by GC, and alternatively an amount insufficient tocause performance problems of release coatings prepared from releasecoating compositions including the polyfunctional organohydrogensiloxanemade by the method described herein.

Starting Material A) Catalyst

Starting material A) in the method described herein is a boroncontaining Lewis acid. The boron containing Lewis acid may be atrivalent boron compound with at least one perfluoroaryl group permolecule, alternatively 1 to 3 perfluoroaryl groups per molecule,alternatively 2 to 3 perfluoroaryl groups per molecule, andalternatively 3 perfluoroaryl groups per molecule. The perfluoroarylgroups may have 6 to 12 carbon atoms, alternatively 6 to 10 carbonatoms, and alternatively 6 carbon atoms. The A) the boron containingLewis Acid catalyst may be selected from the group consisting of(C₅F₄)(C₆F₅)₂B; (C₅F₄)₃B; (C₆F₅)BF₂; BF(C₆F₅)₂; B(C₆F₅)₃; BCl₂(C₆F₅);BCl(C₆F₅)₂; B(C₆H₅)(C₆F₅)₂; B(C₆H₅)₂(C₆F₅); [C₆H₄(mCF₃)]₃B;[C₆H₄(pOCF₃)]₃B; (C₆F₅)B(OH)₂; (C₆F₅)₂BOH; (C₆F₅)₂BH; (C₆F₅)BH₂;(C₇H₁₁)B(C₆F₅)₂; (C₈H₁₄)B(C₆F₅); (C₆F₅)₂B(OC₂H₅); or(C₆F₅)₂B—CH₂CH₂Si(CH₃). Alternatively, the boron containing Lewis acidcatalyst may be tris(pentafluorophenyl)borane of formula B(C₆F₅)₃. Suchboron containing Lewis acids are commercially available from, e.g.,Millipore Sigma of St. Louis, Mo., USA. The amount of starting materialA) will depend on the type and amount of other starting materials used,however, starting material A) may be present in an amount of 50 ppm to6000 ppm based on combined weights of starting materials A), B) and C).Alternatively, the amount may be 50 ppm to 600 ppm on the same basis.

Starting Material B) Hydroxyl Terminated Polydiorganosiloxane

Starting material B) is a hydroxyl terminated polydiorganosiloxane offormula B-1):

where each subscript n is 2 to 2,000, and each R¹ is independentlyselected from the group consisting of monovalent hydrocarbon groups andmonovalent halogenated hydrocarbon groups. Alternatively, subscript nmay have a value such that 2≤n≤1,000, alternatively 5≤n≤900,alternatively 5≤n≤50, and alternatively 5≤n≤15. Alternatively, each R¹may be independently selected from the group consisting of an alkylgroup of 1 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms,an aryl group of 6 to 20 carbon atoms, or a halogenated alkyl group of 1to 20 carbon atoms. Suitable alkyl groups include methyl, ethyl, andpropyl (including n-propyl and isopropyl). Suitable alkenyl groupsinclude vinyl, allyl, and hexenyl. Suitable aryl groups include phenyl.Suitable halogenated alkyl groups include chloromethyl, chloropropyl,and trifluoropropyl. Alternatively, each R¹ may be independentlyselected from the group consisting of methyl, vinyl, phenyl, andtrifluoropropyl.

Hydroxyl terminated polydiorganosiloxanes suitable for use as startingmaterial B) may be prepared by methods known in the art, such ashydrolysis and condensation of the corresponding organohalosilanes orequilibration of cyclic polydiorganosiloxanes. Exemplary hydroxylterminated polydiorganosiloxanes are hydroxyl terminatedpolydimethylsiloxanes. Suitable hydroxyl terminatedpolydimethylsiloxanes are also commercially available, e.g., fromGelest, Inc. of Morrisville, Pa., USA, such as DMS-512, DMS-514,DMS-515, DMS-S21, DMS-527, DMS-541, DMS-532, DMS-533, DMS-535, DMS-542,and DMS-545.

Starting Material C) Cyclic Polyorganohydrogensiloxane

Starting material C) for the method described herein is a cyclicpolyorganohydrogensiloxane of formula C-1): (RHSiO_(2/2))_(v), wheresubscript v is 3 to 12, and each R is an independently selectedmonovalent hydrocarbon group. Alternatively, subscript v may be 4 to 10,alternatively 4 to 8. Alternatively, subscript v may have an averagevalue of 4 to 6, alternatively 4 to 5, and alternatively 4. In formulaC-1), R may be an alkyl group of 1 to 6 carbon atoms. Alternatively, Rmay be methyl, ethyl, or propyl. Alternatively, R may be methyl.Examples of suitable cyclic polyorganohydrogensiloxanes for startingmaterial C) include tetramethylcyclotetrasiloxane,pentamethylcyclopentasiloxane, hexamethylcyclohexasiloxane, andcombinations of two or more thereof. Suitable cyclicpolyorganohydrogensiloxanes are known in the art and are commerciallyavailable, e.g., from Dow Silicones Corporation of Midland, Mich., USA.

The amounts of starting materials B) and C) depend on various factorsincluding the OH content of B) the hydroxyl terminatedpolydiorganosiloxane and the silicon bonded hydrogen (SiH) content of C)the cyclic polyorganohydrogensiloxane. However, amounts are sufficientto provide a molar ratio of SiH in starting material C) to OH instarting material B) (SiH:OH ratio) of 4:1 to 40:1, alternatively 5:1 to20:1, and alternatively 5:1 to 10:1.

Starting Material D) Solvent

A solvent may be used in the method. The solvent may facilitateintroduction of certain starting materials, such as starting material A)the boron containing Lewis acid. Solvents used herein are those thathelp fluidize the starting materials but essentially do not react withany of these starting materials. Solvent may be selected based onsolubility the starting materials and volatility of the solvent. Thesolubility refers to the solvent being sufficient to dissolve and/ordisperse the starting materials. Volatility refers to vapor pressure ofthe solvent.

Suitable solvents may be hydrocarbons. Suitable hydrocarbons includearomatic hydrocarbons such as benzene, toluene, or xylene; and/oraliphatic hydrocarbons such as heptane, hexane, or octane.Alternatively, the solvent may be a halogenated hydrocarbon such asdichloromethane, 1,1,1-trichloroethane or methylene chloride.

The amount of solvent can depend on various factors including the typeof solvent selected and the amount and type of other starting materialsselected. However, the amount of solvent may range from 0.1% to 99%,alternatively 2% to 50%, based on combined weights of starting materialsA), B), and C).

Starting Material E) Neutralizing Agent

Starting material E) is neutralizing agent that may optionally be usedto neutralize starting material A) after the product forms. Alumina,triphenyl amine, triphenyl phosphine, and phenylacetylene are suitableneutralizing agents. Neutralizing agents are known in the art and arecommercially available, e.g., from Millipore Sigma of St. Louis, Mo.,USA. The amount of neutralizing agent depends on various factorsincluding the amount of starting material A), however, starting materialE) may be present in an amount sufficient to provide a weight ratio ofneutralizing agent to boron containing Lewis acid (E:A ratio) of 1:1 to1000:1. Alternatively, when the neutralizing agent is triphenylphosphine or phenylacetylene, the E:A ratio may be 1:1 to 20:1.Alternatively, when the neutralizing agent is alumina, the E:A ratio maybe 100:1 to 1000:1.

Product of the Method

The product of the method described above comprises a) a polyfunctionalorganohydrogensiloxane and a by-product comprising H₂. The product maycomprise a polyfunctional organohydrogensiloxane of unit formula a-1):

[(HRSiO_(2/2))_(v-1)(—RSiO_(2/2))]₂[O—(R¹₂SiO_(2/2))_(n)]_(n′)[(HRSiO_(2/2))_(v-2)(—RSiO_(2/2))₂]_(o′), wheresubscripts v and n and groups R and R¹ are as described above, subscripto′ is 0 to 100 and subscript n′=(o′+1). One skilled in the art wouldrecognize that depending on various factors including the relativeamounts of starting materials B) and C), the product may comprise morethan one polyfunctional organohydrogensiloxane species. Thepolyfunctional organohydrogensiloxane may have an average of more thantwo cyclic moieties and more than two linear moieties per molecule (wheno′>0). Alternatively, subscript v may have an average value of 5,subscript n may have an average value of 10, subscript n′ may be 1 to 2,and subscript o′ may be 0 to 1. Alternatively, subscript v may be 5,subscript n may be 10, subscript n′ may be 2 and subscript o′ may be 1.Alternatively, when subscript o′=0, then in the product comprises apolyfunctional organohydrogensiloxane of formula a-2):

where subscripts n and v, and groups R and R¹ are as described above.One skilled in the art would recognize that polyfunctionalorganohydrogensiloxanes having two or more linear backbone chains, andthree or more cyclic groups, per molecule may also be formed and bepresent in the product, depending on various factors including the molarratio of starting material B) and starting material C) selected for themethod. However, the inventors surprisingly found that using the methoddescribed herein employing the boron containing Lewis acid as startingmaterial A) provided higher selectivity toward the polyfunctionalorganohydrogensiloxane of formula a-1) than previous methods involving aplatinum catalyst. The method provides the benefit of allowing controlof the polyfunctional organohydrogensiloxane architecture to minimizecrosslinking when desired. For example, by controlling ratio of cyclicpolyorganohydrogensiloxane and hydroxyl terminated polydiorganosiloxanecan maximize the amount of polyfunctional organohydrogensiloxane offormula a-1) where subscript o′=0, i.e., with two cyclic moieties linkedvia oxygen atom at the ends of a linear polydiorganosiloxane. Forexample, when the ratio of C) cyclic polyorganohydrogensiloxane and B)hydroxyl terminated polydiorganosiloxane decreases, there are morechances to form crosslinked species. Therefore, starting materials B)and C) may be used in amounts such that the molar ratio of C:B is >6:1.Alternatively, starting materials B) and C) may be used in amounts suchthat SiH:OH ratio is 4:1 to 40:1, alternatively 5:1 to 20:1, andalternatively 5:1 to 10:1. The polyfunctional organohydrogensiloxaneproduced by the method described above may be used in release coatingcompositions, e.g., as a crosslinker or co-crosslinker.

Method for Making Clustered Functional Organopolysiloxane

Alternatively, the method described above may further comprisefunctionalizing the polyfunctional organohydrogensiloxane to form aclustered functional organopolysiloxane. The method described above mayfurther comprise:

combining starting materials comprising

the product described above, or a) the polyfunctionalorganohydrogensiloxane; and

b) a hydrosilylation reaction catalyst; and

c) a reactive species having an average, per molecule at least onealiphatically unsaturated group capable of undergoing an additionreaction with a silicon bonded hydrogen atom of starting material a) thepolyfunctional organohydrogensiloxane, wherein starting material c)further comprises one or more curable groups per molecule. Brieflystated, this method may be performed by modifying the method describedin U.S. Pat. No. 9,593,209. Starting material a) described hereinabovemay be combined with the reactive species and the hydrosilylationreaction catalyst (described as components c) and d), respectively) inthe amounts and under conditions described in U.S. Pat. No. 9,593,209 atcol. 8, line 44 to col. 10, line 47.

Starting Material b) Hydrosilylation Reaction Catalyst

Hydrosilylation reaction catalysts suitable for starting material b) inthe method for functionalizing the polyfunctional organohydrogensiloxaneto form a clustered functional organopolysiloxane are known in the artand are commercially available. Hydrosilylation reaction catalystsinclude platinum group metal catalysts. Such hydrosilylation catalystscan be a metal selected from platinum, rhodium, ruthenium, palladium,osmium, and iridium. Alternatively, the hydrosilylation catalyst may bea compound of such a metal, for example,chloridotris(triphenylphosphane)rhodium(I) (Wilkinson's Catalyst), arhodium diphosphine chelate such as[1,2-bis(diphenylphosphino)ethane]dichlorodirhodium or[1,2-bis(diethylphospino)ethane]dichlorodirhodium, chloroplatinic acid(Speier's Catalyst), chloroplatinic acid hexahydrate, platinumdichloride, and complexes of said compounds with low molecular weightorganopolysiloxanes or platinum compounds microencapsulated in a matrixor coreshell type structure. Complexes of platinum with low molecularweight organopolysiloxanes include1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complexes with platinum(Karstedt's Catalyst) and methylvinylcyclosiloxane complexes withplatinum (Ashby's Catalyst). These complexes may be microencapsulated ina resin matrix. Alternatively, a hydrosilylation catalyst may comprise1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complex with platinum.Exemplary hydrosilylation catalysts are described in U.S. Pat. Nos.3,159,601; 3,220,972; 3,296,291; 3,419,593; 3,516,946; 3,814,730;3,989,668; 4,784,879; 5,036,117; and 5,175,325; and EP 0 347 895 B.Microencapsulated hydrosilylation catalysts and methods of preparingthem are known in the art, as exemplified in U.S. Pat. Nos. 4,766,176and 5,017,654. The amount used may be sufficient to provide 1 ppm to1,000 ppm of platinum group metal based on combined weights of startingmaterials a), b), and c).

Starting Material c) Reactive Species

Starting material c) the reactive species described above forfunctionalizing the polyfunctional organohydrogensiloxane to form theclustered functional organopolysiloxane may comprise a silane of formulac-1): R⁴ _(y)SiR⁵ _((4-y)), where subscript y is 1 to 3, each R⁴ is thealiphatically unsaturated group capable of undergoing an additionreaction, and each R⁵ is an organic group containing a curablefunctionality. Alternatively, subscript y may be 1 to 2. Alternatively,subscript y may be 1. Each R⁴ may be independently selected from thegroup consisting of alkenyl (such as vinyl, allyl, and hexenyl) andalkynyl (such as propynyl or hexynyl). Each R⁵ may be independentlyselected from the group consisting of an organic group containing anacrylate group, an alcohol group, an alkoxy group, an epoxy group, anisocyanate group, a methacrylate group, or a urethane group.Alternatively, each R⁵ may be independently selected from the groupconsisting of an organic group containing an acrylate group, an organicgroup containing an epoxy group, and an organic group containing amethacrylate group. Alternatively, each R⁵ may be an organic groupcontaining an epoxy group. Suitable silanes are known in the art and arecommercially available, e.g., from Dow Silicones Corporation of Midland,Mich., USA or Gelest, Inc. Exemplary silanes includeallyltrimethoxysilane, allyltriethoxysilane, or a combination thereof.

Alternatively, starting material c) may comprise an organic compoundthat does not contain a silicon atom, e.g., of formula c-2): R⁶R⁷, whereeach R⁶ is an aliphatically unsaturated group capable of undergoing anaddition reaction, and each R⁷ is the curable group. Each R⁶ may beindependently selected from the group consisting of alkenyl (such asvinyl, allyl, and hexenyl) and alkynyl (such as propynyl or hexynyl).Each R⁷ may be independently selected from the group consisting of anorganic group containing an acrylate group, alcohol group, alkoxy group,epoxy group, isocyanate group, methacrylate group, and urethane group.Alternatively, each R⁷ may be selected from the group consisting of anorganic group containing an acrylate group, epoxy group, andmethacrylate group. Alternatively, each R⁷ may be an organic groupcontaining an epoxy group. Examples of suitable compounds of formulac-2) include allyl acrylate, allyl glycidyl ether, allyl methacrylate,and combinations thereof. Alternatively, c-2) may be allyl glycidylether. Alternatively, c-2) may be allyl methacrylate. Suitable compoundsof formula c-2) are known in the art and are commercially available,e.g., from Millipore Sigma of St. Louis, Mo., U.S.A.

The starting materials used in the method for making the clusteredfunctional organosiloxane may optionally further comprise one or moreadditional starting materials. The additional starting materials may bethose additional ingredients disclosed in U.S. Pat. No. 9,593,209 atcol. 10, line 48 to col. 16, line 17. The additional starting materialsselected from the group consisting of filler, with or without treatingagent, non-reactive resin, chain extender, endcapper, and catalystinhibitor.

The method described above produces a product comprising a′) a clusteredfunctional organopolysiloxane, or masterbatch of clustered functionalorganopolysiloxane with the filler and/or non-reactive resin. Theproduct may comprise a clustered functional organosiloxane of unitformula a′-1): [(HRSiO_(2/2))_(v-1)(—RSiO_(2/2))]₂[O—(R¹₂SiO_(2/2))_(n)]_(n′)[(R⁸RSiO_(2/2))_(v-2)(—RSiO_(2/2))₂]_(o′), wheresubscripts v, n, n′ and o′, and groups R, and R¹, are as describedabove; and each R⁸ is independently selected from the group consistingof H and a curable group, with the proviso that at least one R⁸ permolecule is a curable group. Alternatively, 1 to 4 instances of R⁸ permolecule are curable groups (other than hydrogen). Alternatively 1 to 3,alternatively 1 to 2, and alternatively an average of two R⁸ permolecule are curable groups (other than hydrogen). The curable group forR⁸ is derived from starting material c) the reactive species describedabove. The curable group for R⁸ may be independently selected from thegroup consisting of R^(4′)SiR⁵ _((4-y)), and R^(6′)R⁷, where R^(4′) andR^(6′) are divalent hydrocarbon groups produced via hydrosilylationreaction of the aliphatically unsaturated group of starting material c)and a silicon bonded hydrogen atom of starting material a).Alternatively, subscript v may have an average value of 5, subscript nmay have an average value of 10, subscript n′ may be 1 to 2, andsubscript o′ may be 0 to 1. Alternatively, subscript v may be 5,subscript n may be 10, subscript n′ may be 2 and subscript o′ may be 1.One skilled in the art would recognize that depending on various factorsincluding the relative amounts of starting materials B) and C) used tomake the organohydrogensiloxane, the product may comprise more than oneclustered functional organosiloxane species. The clustered functionalorganosiloxane may have an average of more than two cyclic moieties andmore than two linear moieties per molecule (when o′>0). Alternatively,when subscript o′=0, then in the product comprises a clusteredfunctional organopolysiloxane of formula a′-2):

where R, R¹, R⁸, and subscript n and subscript v are as described above.

The clustered functional organosiloxane prepared as described above maybe used in an adhesive composition, such as a thermal radical curableadhesive composition as, e.g., an additive.

The clustered functional organosiloxane may be used, e.g., as anadditive in an adhesive composition. Without wishing to be bound bytheory, it is thought that a′) the clustered functional organosiloxanemay provide one or more benefits of 1) faster cure to the adhesivecomposition (as compared to a comparable adhesive composition notcontaining a′) the clustered functional organosiloxane described above),and 2) improved tensile and elongation properties of an adhesiveprepared by curing the adhesive composition, and/or 3) improvedcrosslinking of the adhesive composition.

Curable Composition

The products, a) the polyfunctional organohydrogensiloxane, and a′) theclustered functional organopolysiloxane are useful in curablecompositions. The curable composition may comprise:

(I) one or more of the above described products, a) polyfunctionalorganohydrogensiloxane, and a′) clustered functional organopolysiloxane;and(II) a curing agent.

The curing agent selected will depend on the type and amount of curablesubstituents on starting material (I). For example, the curablesubstituent may be the SiH e.g., when a) the polyfunctionalorganohydrogensiloxane is included in the curable composition and/orwhen a′) the clustered functional organosiloxane has SiH functionalityin addition to the curable group introduced by starting material c) inthe method described above. Alternatively, the curable substituent maybe the curable group introduced by starting material c) the reactivespecies used to make a′) the clustered functional organosiloxane, asdescribed above.

For example, when starting material (I) has SiH functionality, (II) thecuring agent may be a hydrosilylation reaction catalyst, as exemplifiedby those described above for starting material b) in the method forfunctionalizing the polyfunctional organohydrogensiloxane describedabove.

For example, when starting material (I) comprises the a′) clusteredfunctional organosiloxane with radical curable groups (such as organicgroups containing epoxy, acrylate, or methacrylate functionality, thecuring agent may comprise a radical initiator as (II) the curing agent.The radical initiator may be a thermal radical initiator, a radiationradical initiator, or a redox reagent. Thermal radical initiatorsinclude peroxides, which are known in the art and are commerciallyavailable as disclosed in U.S. Pat. No. 9,593,209 at col. 16, line 49 tocol. 17, line 26. Thermal radical initiators may be used in an amount of0.01% to 15%, alternatively 0.1% to 5% and alternatively 0.1% to 2%based on combined weights of all starting materials in the curablecomposition.

Alternatively, the radical initiator may be a radiation photoinitiator.Radiation photoinitiators are known in the art and include cationicphotoinitiators such as onium salts, and radiation photoinitiators aredisclosed in U.S. Pat. No. 9,593,209 at col. 17, line 27 to col. 18,line 40. Suitable radiation photoinitiators may be used in the curablecomposition in an amount of 0.01% to 15%, alternatively 0.1% to 10%,alternatively 0.1% to 5% and alternatively 0.1% to 2% based combinedweights of all starting materials in the curable composition.

Alternatively, the radical initiator may be a redox reagent, such asthose disclosed in U.S. Pat. No. 9,593,209 at col. 21, lines 33 to 53.

Alternatively, when starting material (I) comprises the a′) clusteredfunctional organosiloxane with organic groups having OH, alkoxy, orother hydrolyzable groups, (II) the curing agent may comprise acondensation reaction catalyst, in an amount of 0.001% to 5% based oncombined weights of all starting materials in the curable composition.Exemplary condensation reaction catalysts are those disclosed in U.S.Pat. No. 9,593,209 at col. 18, line 41 to 19, line 15.

Alternatively, when starting material (I) comprises the a′) clusteredfunctional organosiloxane, (II) the curing agent may comprise anorganoborane amine complex. Suitable organoborane amine complexes aredisclosed, for example, in U.S. Pat. No. 9,593,209 at col. 19, line 16to col. 21, line 33.

Alternatively, when starting material (I) comprises the a′) clusteredfunctional organosiloxane with organic groups having isocyanatefunctionality or urethane functionality, (II) the curing agent maycomprise a compound having two or more carbinol groups, such as apolyol, or an amine functional compound. Examples of such curing agentsare disclosed at col. 21, lines 54 to 63.

Alternatively, when starting material (I) has more than one type ofcurable substituent, more than one type of curing agent may be used asstarting material (II) in the curable composition. For example, acombination of a radical initiator and a condensation reaction catalystmay be used when starting material (I) has both radical curable groupsand condensation reaction curable groups, such as epoxy and alkoxy.Alternatively, the combination of a hydrosilylation reaction catalystand a condensation reaction catalyst may be used when starting material(I) has both SiH functionality and condensation reaction curable groups,such as alkoxy.

The curable composition may optionally further comprise one or moreadditional starting materials. These are exemplified by (III) acrosslinker, (IV) a solvent, (V) an adhesion promoter, (VI) a colorant,(VII) a reactive diluent, (VIII) a corrosion inhibitor, (IX) apolymerization inhibitor, (X) a filler, (XI) a filler treating agent,(XII) an acid acceptor, and a combination thereof. Suitable additionalstarting materials are described and exemplified as other optionalingredients in U.S. Pat. No. 9,592,209 at col. 22, line 5 to col. 29,line 8. Other additional starting materials may be added. For example,the curable composition may optionally further comprise (XIII) areactive resin and polymer, (XIV) a dual cure compound, or both. Thereactive resin and polymer for starting material (XIII) are known in theart, for example, see U.S. Pat. No. 9,670,392 at col. 16, line 21 tocol. 18, line 35.

Thermal Radical Curable Composition

The curable composition may be a thermal radical curable composition.The thermal radical curable composition may be made as described in U.S.Pat. No. 9,670,392 by replacing the clustered functional organosiloxanedescribed therein as component (I) with the clustered functionalorganopolysiloxane prepared as described for starting material a′)hereinabove. The thermal radical curable composition may comprise:

(I) the clustered functional organopolysiloxane described above asstarting material a′), or the product containing a′) the clusteredfunctional organopolysiloxane,(II) the curing agent comprising

(a) the radical initiator, and

(b) the condensation reaction catalyst,

(III) the crosslinker, and(XIII) the reactive resin and polymer.

The thermal radical cure composition may further comprise (XIV) the dualcure compound (which is an organosilicon compound having bothhydrolyzable and free radical reactive groups), (VIII) the corrosioninhibitor, and (V) the adhesion promoter, all of which startingmaterials are as described above.

Adhesive Composition

Alternatively, the curable composition may be an adhesive composition.The adhesive composition may comprise:

A) the clustered functional organopolysiloxane described above asstarting material a′), or the product containing a′) the clusteredfunctional organopolysiloxane, where the clustered functionalorganopolysiloxane has acrylate functional groups, epoxy functionalgroups, and/or methacrylate functional groups,

B) a reactive resin and polymer,

C) a condensation reaction catalyst, and

D) a free radical initiator.

Starting Material B) Reactive Resin and Polymer

Starting material B) in the adhesive composition is a reactive resin andpolymer. The reactive resin and polymer may be (XIII) the reactive resinand polymer described above as starting material (XIII), see U.S. Pat.No. 9,670,392. Alternatively, the reactive resin and polymer may be apoly-alkoxy endblocked resin-polymer blend prepared as described in U.S.Provisional Patent Application Ser. No. 62/548,558 filed on 22 Aug.2017. The poly-alkoxy endblocked resin-polymer blend comprises areaction product of

i) a siloxane resin comprising units of formulae (R^(2′) ₃SiO_(1/2)) and(SiO_(4/2)), where each R^(2′) is independently a monovalent hydrocarbongroup, with the proviso that at least one R^(2′) per molecule hasaliphatic unsaturation, wherein the siloxane resin has a molar ratio of(R^(2′) ₃SiO_(1/2)) units (M units) to (SiO_(4/2)) units (Q units)ranging from 0.5:1 to 1.5:1 (M:Q ratio),

ii) a polydiorganosiloxane comprising units of formulae (R^(2′)₃SiO_(1/2))_(ii) and (R^(2′) ₂SiO_(2/2))_(hh) (D units), where subscripthh is 20 to 1000 and subscript ii has an average value of 2, and

iii) an alkoxy-functional organohydrogensiloxane oligomer. Thealkoxy-functional organohydrogensiloxane oligomer has unit formula

(HR²² ₂SiO_(1/2))_(ppp)(R²² ₃SiO_(1/2))_(qqq)(HR²²SiO_(2/2))_(rrr) (R²²₂SiO_(2/2))_(sss)(R²²SiO_(3/2))_(ttt)(HSiO_(3/2))_(uuu)(SiO_(4/2))_(kk),where each D¹ independently represents a divalent hydrocarbon group of 2to 18 carbon atoms; each R²² independently represents a monovalenthydrocarbon group of 1 to 18 carbon atoms or a monovalent halogenatedhydrocarbon group of 1 to 18 carbon atoms (such as those described abovefor R¹), each R²³ is independently a monovalent hydrocarbon group of 1to 18 carbon atoms (such as those described above for R¹), subscript nnnis 0 or 1, subscript 000 is 0, subscripts qqq, sss, and ttt have valuessuch that 5≥qqq≥0, 5≥sss≥0, subscript ttt is 0 or 1, subscript kk is 0or 1, subscript nnn>0, and a quantity(mmm+ppp+qqq+rrr+sss+ttt+uuu+kk)≤50, with the proviso that >90 mol % ofall D¹ groups in the endblocker are linear; and

iv) a hydrosilylation reaction catalyst. Each D¹ may be exemplified byan alkylene group such as ethylene, propylene, butylene, or hexylene; anarylene group such as phenylene, or an alkylarylene group such as:

Alternatively, each D¹ is an alkylene group such as ethylene orpropylene; alternatively ethylene.

Starting Material C)—Condensation Reaction Catalyst

Starting material C) in the adhesive composition described above is acondensation reaction catalyst. The condensation reaction catalyst maybe selected from common condensation catalysts that are effective forsilanol-silanol condensation reaction, which include organometalliccompounds, amines, and a wide range of organic and inorganic bases andacids. Organometallic compounds include organic compounds of tin,titanium, zinc, zirconium, hafnium, and others. The condensationreaction catalysts can be an organotin compound and an organotitaniumcompound. Exemplary organotin compounds may be selected from the groupconsisting of: a) stannic salts of carboxylic acids such as i) dibutyltin dilaurate, ii) dimethyl tin dilaurate, iii) di-(n-butyl)tinbis-ketonate, iv) dibutyl tin diacetate, v) dibutyl tin maleate, vi)dibutyl tin diacetylacetonate, vii) dibutyl tin dimethoxide, viii)carbomethoxyphenyl tin tris-uberate, ix) dibutyl tin dioctanoate, x)dibutyl tin diformate, xi) isobutyl tin triceroate, xii) dimethyl tindibutyrate, xiii) dimethyl tin di-neodeconoate, xiv) dibutyl tindi-neodeconoate, xv) triethyl tin tartrate, xvi) dibutyl tin dibenzoate,xvii) butyltintri-2-ethylhexanoate, xviii) dioctyl tin diacetate, xix)tin octylate, xx) tin oleate, xxi) tin butyrate, xxii) tin naphthenate,xxiii) dimethyl tin dichloride; b) tin (II) salts of organic carboxylicacids such as xxiv) tin (II) diacetate, xxv) tin (II) dioctanoate, xxvi)tin (II) diethylhexanoate, xxvii) tin (II) dilaurate, c) stannous saltsof carboxylic acids such as xxviii) stannous octoate, xxix) stannousoleate, xxx) stannous acetate, xxxi) stannous laurate, xxxii) stannousstearate, xxxiii) stannous naphthanate, xxxiv) stannous hexanoate, xxxv)stannous succinate, xxxvi) stannous caprylate, and d) a combination oftwo or more of i) to xxxvi). Exemplary organotitanium compounds may beselected from the group consisting of: i) tetra-n-butyl titanate, ii)tetraisopropyl titanate, iii) tetra-t-butyl titanate, iv)tetrakis(2-ethylhexyl) titanate, v) acetylacetonate titanate chelate,vi) ethyl acetoacetate titanate chelate, vii) triethanolamine titanatechelate, viii) tri-n-butyl titanate, and ix) a combination of two ormore of i), ii), iii), iv), v), vi), vii), and viii).

The amount of condensation reaction catalyst in the adhesive compositiondepends on various factors including the selection of the other startingmaterials, whether any additional starting materials are added, and theend use of the adhesive composition. However, the condensation reactioncatalyst may be present in an amount ranging from 0.01% to 25% based oncombined weights of all starting materials in the adhesive composition.Alternatively, the condensation reaction catalyst may be present in anamount of 0.1% to 25%, alternatively 0.1% to 15%, alternatively 0.5% to15%, alternatively 0.5% to 10%, alternatively 0.1% to 5%.

Starting Material D)—Free Radical Initiator

Starting material D) in the adhesive composition described above is afree radical initiator. The free radical initiator may comprise an azocompound or an organic peroxide compound. Suitable azo compounds includeazobenzene, azobenzene-p-sulfonic acid, azobisdimethylvaleronitrile,azobisisobutyronitrile, and a combination thereof. Suitable organicperoxide compounds include dialkyl peroxides, diaryl peroxides, diacylperoxides, alkyl hydroperoxides, and aryl hydroperoxides. Specificorganic peroxide compounds are as described above for starting material(II). Alternatively, the organic peroxide may be exemplified by benzoylperoxide; dibenzoyl peroxide; 4-monochlorobenzoyl peroxide; dicumylperoxide; tert-butylperoxybenzoate; tert-butyl cumyl peroxide;tert-butyloxide 2,5-dimethyl-2,5-di-tert-butylperoxyhexane;2,4-dichlorobenzoyl peroxide; di-tertbutylperoxy-diisopropyl benzene;1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane;2,5-di-tert-butylperoxyhexane-3,2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; cumyl-tert-butyl peroxide; or combinations of two or morethereof.

The amount of free radical initiator added to the adhesive compositiondepends on various factors including the type and amount of condensationreaction catalyst selected and the selection of other starting materialsin the adhesive composition, however, the free radical initiator may bepresent in an amount of 0.1% to 5%, alternatively 0.2% to 3%,alternatively 0.5% to 2%, based on the combined weights of all startingmaterials in the adhesive composition.

Additional Starting Materials in the Adhesive Composition

The adhesive composition described above may further comprise one ormore additional starting materials (distinct from and added in additionto starting materials A), B), C) and D) described above). The additionalstarting materials may be selected from the group consisting of E) adual cure compound, F) an adhesion promoter, G) a corrosion inhibitor,H) a rheology modifier, I) a drying agent, J) a crosslinker, K) afiller, L) a spacer, M) an acid scavenger, N) a silanol functionalpolydiorganosiloxane, O) a fluorescent optical brightener, P) a chaintransfer agent, Q) a (meth)acrylate monomer, R) a poly-alkoxy terminatedpolydiorganosiloxane, S) a colorant, and two or more of E), F), G), H),I), J), K), L), M), N), O), P), Q), R), and S).

Starting Material E)—Dual Cure Compound

The adhesive composition described above may optionally further comprisestarting material E) a dual cure compound. The dual cure compound is anorganosilicon compound having, per molecule, at least one hydrolyzablegroup and at least one free radical reactive group. The organosiliconcompound for starting material E) may comprise a silane of formula R¹⁴_(mm)R²² _(nn)SiX_((4-mm-nn)), where R²² is as described above, R¹⁴ is acurable group (such as an acrylate functional group, an epoxy functionalgroup or a methacrylate functional group), X is a hydrolysable group,subscript mm is 1 to 2, subscript nn is 0 to 2, and a quantity (mm+nn)is 2 to 3.

Each X independently represents a hydrolyzable group, which may beselected from an acetamido group, an acyloxy group such as acetoxy, analkoxy group, an amido group, an amino group, an aminoxy group, an oximogroup, a ketoximo group, and a methylacetamido group. X is not ahydroxyl group. Alternatively, each X may be an acetoxy group or analkoxy group. Alternatively, each X is an alkoxy group, such as methoxy,ethoxy, propoxy or butoxy; alternatively methoxy.

Alternatively, the organosilicon compound for starting material E) maycomprise a polyorganosiloxane of unit formula: (X_(mm)R²²_((3-mm))SiO_(1/2))_(oo)(R¹⁴R²² ₂SiO_(1/2))_(pp)(R²²₂SiO_(2/2))_(qq)(R²²XSiO_(2/2))_(rr)(R¹⁴R²²SiO_(2/2))_(ss)(R¹⁴R²²SiO_(3/2))_(ww)(R²²SiO_(3/2))_(tt)(SiO_(4/2))_(uu),where R²², R¹⁴, and X and subscript mm are as described above, subscriptoo≥0, subscript pp≥0, subscript qq≥0, subscript rr≥0, subscript ss≥0,subscript ww≥0, subscript tt≥0, and subscript uu≥0, with the provisosthat a quantity (oo+rr)≥1, a quantity (pp+ss+ww)≥1, and a quantity(oo+pp+qq+rr+ss+ww+tt+uu)>2. Alternatively, subscript oo is 0 to 100,alternatively 0 to 50, alternatively 0 to 20, alternatively 0 to 10,alternatively, 1 to 50, alternatively, 1 to 20, and alternatively 1 to10. Alternatively, subscript pp may be 0 to 100, alternatively 0 to 50,alternatively 0 to 20, alternatively 0 to 10, alternatively 1 to 50,alternatively 1 to 20, and alternatively 1 to 10. Alternatively,subscript qq is 0 to 1,000, alternatively 0 to 500, alternatively 0 to200, alternatively 0 to 100, alternatively 1 to 500, alternatively 1 to200, and alternatively 1 to 100. Alternatively, subscript rr is 0 to100, alternatively 0 to 50, alternatively 0 to 20; alternatively 0 to10, alternatively 1 to 50, alternatively 1 to 20, and alternatively 1 to10. Alternatively, subscript ss is 0 to 100, alternatively 0 to 50,alternatively 0 to 20, alternatively 0 to 10, alternatively 1 to 50,alternatively 1 to 20, and alternatively 1 to 10. Alternatively,subscript ww is 0 to 100, alternatively 0 to 50, alternatively 0 to 20,alternatively 0 to 10, alternatively 1 to 50, alternatively 1 to 20, andalternatively 1 to 10. Alternatively, subscript tt is 0 to 1,000,alternatively 0 to 500, alternatively 0 to 200; alternatively 0 to 100,alternatively 1 to 500, alternatively 1 to 200, and alternatively 1 to100. Alternatively, subscript uu is 0 to 1,000, alternatively 0 to 500,alternatively 0 to 200, alternatively 0 to 100, alternatively 1 to 500,alternatively 1 to 200, and alternatively 1 to 100.

Examples of starting material E) include silanes, such asmethacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane,acryloxypropyltriethoxysilane, methacryloxypropyltriethoxysilane,methacryloxypropylmethyldimethoxysilane,acryloxypropylmethyldimethoxysilane,acryloxypropyldimethylmethoxysilane, andmethacryloxypropyldimethylmethoxysilane.

The amount of dual cure compound in the adhesive composition depends onvarious factors including the selection of the other starting materials,whether any additional starting materials are added, and the end use ofthe composition. However, the dual cure compound may be present in anamount ranging from 0.01% to 25% based on combined weights of allstarting materials in the adhesive composition. Alternatively, the dualcure compound may be present in an amount of 0.1% to 25%, alternatively0.1% to 15%, alternatively 0.5% to 15%, alternatively 0.5% to 10%,alternatively 0.1% to 5%.

Starting Material F)—Adhesion Promoter

The adhesive composition described above may optionally further compriseF) an adhesion promoter. Suitable adhesion promoters may comprise atransition metal chelate, a hydrocarbonoxysilane such as analkoxysilane, a combination of an alkoxysilane and a hydroxy-functionalpolyorganosiloxane, an aminofunctional silane, or a combination thereof.Adhesion promoters may comprise silanes having the formula R¹⁵ _(aaa)R¹⁶_(bbb)Si(OR¹⁷)_(4-(aaa+bbb)) where each R¹⁵ is independently amonovalent organic group having at least 3 carbon atoms; R¹⁶ contains atleast one SiC bonded substituent having an adhesion-promoting group,such as amino, epoxy, mercapto or acrylate groups; each R¹⁷ isindependently a saturated hydrocarbon group such as an alkyl group of 1to 4 carbon atoms; subscript aaa has a value ranging from 0 to 2;subscript bbb is either 1 or 2; and a quantity (aaa+bbb) is not greaterthan 3. Alternatively, the adhesion promoter may comprise a partialcondensate of the above silane. Alternatively, the adhesion promoter maycomprise a combination of an alkoxysilane and a hydroxy-functionalpolyorganosiloxane, such as trimethoxysilyl terminatedpolydimethylsiloxane, which is commercially available from Dow SiliconesCorporation of Midland, Mich., USA.

Alternatively, the adhesion promoter may comprise an unsaturated orepoxy-functional compound. The adhesion promoter may comprise anunsaturated or epoxy-functional alkoxysilane. For example, thefunctional alkoxysilane can have the formula R¹⁸_(ccc)Si(OR¹⁹)_((4-ccc)), where subscript ccc is 1, 2, or 3,alternatively subscript ccc is 1. Each R¹⁸ is independently a monovalentorganic group with the proviso that at least one R¹⁸ is an unsaturatedorganic group or an epoxy-functional organic group. Epoxy-functionalorganic groups for R¹⁸ are exemplified by 3-glycidoxypropyl and(epoxycyclohexyl)ethyl. Unsaturated organic groups for R¹⁸ areexemplified by 3-methacryloyloxypropyl, 3-acryloyloxypropyl, andunsaturated monovalent hydrocarbon groups such as vinyl, allyl, hexenyl,undecylenyl. Each R¹⁹ is independently a saturated hydrocarbon group of1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. R¹⁹ isexemplified by methyl, ethyl, propyl, and butyl.

Examples of suitable epoxy-functional alkoxysilanes include3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,(epoxycyclohexyl)ethyldimethoxysilane,(epoxycyclohexyl)ethyldiethoxysilane,(epoxycyclohexyl)ethyltrimethoxysilane,(epoxycyclohexyl)ethyltriethoxysilane, and combinations thereof.Examples of suitable unsaturated alkoxysilanes includevinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane,hexenyltrimethoxysilane, undecylenyltrimethoxysilane,3-methacryloyloxypropyl trimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyl trimethoxysilane,3-acryloyloxypropyl triethoxysilane, and combinations thereof.

Alternatively, the adhesion promoter may comprise an epoxy-functionalsiloxane such as a reaction product of a hydroxy-terminatedpolyorganosiloxane with an epoxy-functional alkoxysilane, as describedabove, or a physical blend of the hydroxy-terminated polyorganosiloxanewith the epoxy-functional alkoxysilane. The adhesion promoter maycomprise a combination of an epoxy-functional alkoxysilane and anepoxy-functional siloxane. For example, the adhesion promoter isexemplified by a mixture of 3-glycidoxypropyltrimethoxysilane and areaction product of hydroxy-terminated methylvinylsiloxane with3-glycidoxypropyltrimethoxysilane, or a mixture of3-glycidoxypropyltrimethoxysilane and a hydroxy-terminatedmethylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilaneand a hydroxy-terminated methylvinyl/dimethylsiloxane copolymer.

Alternatively, the adhesion promoter may comprise an aminofunctionalsilane, such as an aminofunctional alkoxysilane exemplified byH₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)₃,H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃,H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂,CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, and a combination thereof.

Alternatively, the adhesion promoter may comprise a transition metalchelate. Suitable transition metal chelates include titanates,zirconates such as zirconium acetylacetonate, aluminum chelates such asaluminum acetylacetonate, and combinations thereof.

Alternatively, the adhesion promoter may comprise a triazine basedcompound that bears functionality to react with starting material A),starting material B), or, when present, starting material E), or two ormore thereof. The triazine ring can be mono-, di-, or tri-substitutedand at least one of the substitute group is the functionality to react.The functionality can be a free radical reactive one or a condensationreactive one. Examples of triazine compound with free radical reactivefunctional groups include triallylisocyanurate,diallylpropylisocyanurate, tri-(methacryloxypropyl)isocyanurate,triallyloxytriazine, trimethacryloxytriazine,triacryloylhexahydrotriazine, and tris[2-(acryloyloxy)ethyl]isocyanurate. Examples of triazine compound with condensation reactivegroup include 2,4,6-tris(methyldimethoxysilyl)triazine, andtris[3-(trimethoxysilyl)propyl] isocyanurate.

The exact amount of adhesion promoter depends on various factorsincluding the selection and amounts of other starting materials in theadhesive composition. However, the adhesion promoter, when present, maybe added to the adhesive composition in an amount of 0.01 to 50 weightparts based on combined weight of all starting materials in thecomposition, alternatively 0.01 to 10 weight parts, and alternatively0.01 to 5 weight parts. Examples of suitable adhesion promoters aredescribed in U.S. Pat. No. 9,156,948.

Starting Material G)—Corrosion Inhibitor

The adhesive composition may optionally further comprise startingmaterial G), a corrosion inhibitor. Examples of suitable corrosioninhibitors include benzotriazole, mercaptobenzothiazole,mercaptabenzotriazole and commercially available corrosion inhibitorssuch as 2-mercaptobenzothiazole from Millipore Sigma,2,5-dimercapto-1,3,4-thiadiazole derivative (CUVAN™ 826) andalkylthiadiazole (CUVAN™ 484) from R. T. Vanderbilt of Norwalk, Conn.,U.S.A. Examples of suitable corrosion inhibitors are exemplified bythose described in U.S. Pat. No. 9,156,948. When present, the amount ofcorrosion inhibitor) may be 0.05% to 0.5% based on combined weights ofall starting materials in the adhesive composition.

Starting Material H)—Rheology Modifier

The adhesive composition may optionally further comprise up to 5%,alternatively 1% to 2% based on combined weights of all startingmaterials in the composition, of starting material H) a rheologymodifier. Rheology modifiers are commercially available. Examples ofsuitable rheology modifiers include polyamides, hydrogenated castor oilderivatives, metal soaps, microcrystalline waxes, and combinationsthereof. Examples of suitable rheology modifiers are exemplified bythose described in U.S. Pat. No. 9,156,948. The amount of rheologymodifier depends on various factors including the specific rheologymodifier selected and the selections of the other starting materialsused in the composition. However, the amount of rheology modifier may be0 parts to 20 parts, alternatively 1 part to 15 parts, and alternatively1 part to 5 parts based on combined weights of all starting materials inthe adhesive composition.

Starting Material I)—Drying Agent

The composition described above may optionally further comprise startingmaterial I) a drying agent. The drying agent binds water from varioussources. For example, the drying agent may bind by-products of thecondensation reaction, such as water and alcohols. Examples of suitabledrying agents are disclosed, for example, in U.S. Pat. No. 9,156,948.Examples of suitable adsorbents for the drying agent may be inorganicparticulates, e.g., zeolites such as chabasite, mordenite, and analcite;molecular sieves such as alkali metal alumino silicates, silica gel,silica-magnesia gel, activated carbon, activated alumina, calcium oxide,and combinations thereof. The adsorbent may have a particle size of 10μm or less. The adsorbent may have average pore size sufficient toadsorb water and alcohols, for example 10 Å (Angstroms) or less.

Alternatively, the drying agent may bind the water and/or otherby-products by chemical means. An amount of a silane crosslinker addedto the composition (in addition to any silane crosslinker used asstarting material J)) may function as a chemical drying agent. Withoutwishing to be bound by theory, it is thought that the chemical dryingagent may be added to the dry part of a multiple part composition tokeep the composition free from water after the parts of the compositionare mixed together. For example, alkoxysilanes suitable as drying agentsinclude vinyltrimethoxysilane, vinyltriethoxysilane,methyltrimethoxysilane, isobutyltrimethoxysilane, and combinationsthereof. The amount of drying agent depends on the specific drying agentselected. However, when starting material I) is a chemical drying agent,the amount may range from 0 parts to 15 parts, alternatively 0 parts to10 parts, alternatively 0 parts to 5 parts, alternatively 0.1 parts to0.5 parts, based on combined weights of all starting materials in thecomposition.

Starting Material J)—Crosslinker

The composition described above may optionally further comprise startingmaterial J), a crosslinker. The crosslinker may comprise a silanecrosslinker having hydrolyzable groups or partial or full hydrolysisproducts thereof. The crosslinker has an average, per molecule, ofgreater than two substituents reactive with the hydrolyzable groups onstarting material B).

Examples of suitable silane crosslinkers may have the general formulaR²⁰ _(ddd)Si(R²¹)_((4-ddd)), where each R²⁰ is independently amonovalent hydrocarbon group such as an alkyl group; each R²¹ is ahydrolyzable substituent, which may be a group the same as X describedabove. Alternatively, each R²¹ may be, for example, a hydrogen atom, ahalogen atom, an acetamido group, an acyloxy group such as acetoxy, analkoxy group, an amido group, an amino group, an aminoxy group, ahydroxyl group, an oximo group, a ketoximo group, or a methylacetamidogroup; and each instance of subscript ii may be 0, 1, 2, or 3. For thesilane crosslinker, subscript ddd has an average value greater than 2.Alternatively, subscript ddd may have a value ranging from 3 to 4.Alternatively, each R²¹ may be independently selected from hydroxyl,alkoxy, acetoxy, amide, or oxime. Alternatively, the silane crosslinkermay be selected from an acyloxysilane, an alkoxysilane, aketoximosilane, and an oximosilane.

The silane crosslinker may comprise an alkoxysilane exemplified by adialkoxysilane, such as a dialkyldialkoxysilane; a trialkoxysilane, suchas an alkyltrialkoxysilane; a tetraalkoxysilane; or partial or fullhydrolysis products thereof, or another combination thereof. Examples ofsuitable trialkoxysilanes include methyltrimethoxysilane,methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,isobutyltrimethoxysilane, isobutyltriethoxysilane, and a combinationthereof, and alternatively methyltrimethoxysilane. Examples of suitabletetraalkoxysilanes include tetraethoxysilane. Alternatively, the silanecrosslinker may comprise an acyloxysilane, such as an acetoxysilane.Acetoxysilanes include a tetraacetoxysilane, an organotriacetoxysilane,a diorganodiacetoxysilane, or a combination thereof. Exemplaryacetoxysilanes include, but are not limited to, tetraacetoxysilane,methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane,propyltriacetoxysilane, butyltriacetoxysilane, phenyltriacetoxysilane,octyltriacetoxysilane, dimethyldiacetoxysilane,phenylmethyldiacetoxysilane, vinylmethyldiacetoxysilane, diphenyldiacetoxysilane, tetraacetoxysilane, and combinations thereof.Alternatively, the crosslinker may comprise organotriacetoxysilanes, forexample mixtures comprising methyltriacetoxysilane andethyltriacetoxysilane. Examples of silanes suitable for startingmaterial J) containing both alkoxy and acetoxy groups that may be usedin the composition include methyldiacetoxymethoxysilane,methylacetoxydimethoxysilane, vinyldiacetoxymethoxysilane,vinylacetoxydimethoxysilane, methyldiacetoxyethoxysilane,metylacetoxydiethoxysilane, and combinations thereof.

Alternatively, the crosslinker may comprise an aminofunctional such asH₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)₃,H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃,H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂,CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, or a combination thereof, and acombination thereof. Examples of suitable silane crosslinkers aredisclosed in U.S. Pat. No. 9,156,948.

Alternatively, the crosslinker may comprise a multifunctional(meth)acrylate crosslinker, such as a di(meth)acrylate exemplified Suchcrosslinkers are exemplified by ethylene glycol dimethacrylate, ethyleneglycol diacrylate, triethylene glycol dimethacrylate, diethylene glycolbismethacryloxy carbonate, polyethylene glycol diacrylate, tetraethyleneglycol dimethacrylate, diglycerol diacrylate, diethylene glycoldimethacrylate, pentaerythritol triacrylate, trimethylolpropanetriglycidyl ether, trimethylolpropanetris(2-methyl-1-aziridine)propionate, trimethylol propanetrimethacrylate, acrylate tipped urethane containing prepolymers,polyether diacrylates, and dimethacrylates, and combinations of two ormore thereof. Suitable multifunctional (meth)acrylate crosslinkers aredisclosed, for example, in U.S. Pat. No. 8,304,543 at col. 11 lines46-65.

When present, the crosslinker may be added in an amount ranging from0.1% to 10% based on the combined weights of all starting materials inthe adhesive composition.

Starting Material K)—Filler

The composition described above may optionally further comprise K) afiller. The filler may comprise a reinforcing filler, an extendingfiller, a conductive filler, or a combination thereof. For example, thecomposition may optionally further comprise starting material (K1), areinforcing filler, which when present may be added in an amount of 0.1%to 95%, alternatively 1% to 60%, based on combined weights of allstarting materials in the adhesive composition. The exact amount ofstarting material (K1) depends on various factors including the form ofthe reaction product of the composition and whether any other fillersare added. Examples of suitable reinforcing fillers include reinforcingsilica fillers such as fume silica, silica aerogel, silica xerogel, andprecipitated silica. Fumed silicas are known in the art and commerciallyavailable; e.g., fumed silica sold under the name CAB-O-SIL by CabotCorporation of Massachusetts, U.S.A.

The adhesive composition may optionally further comprise startingmaterial (K2) an extending filler in an amount ranging from 0.1% to 95%,alternatively 1% to 60%, and alternatively 1% to 20%, based on combinedweights of all starting materials in the adhesive composition. Examplesof extending fillers include crushed quartz, aluminium oxide, magnesiumoxide, calcium carbonate such as precipitated calcium carbonate, zincoxide, talc, diatomaceous earth, iron oxide, clays, mica, chalk,titanium dioxide, zirconia, sand, carbon black, graphite, or acombination thereof. Extending fillers are known in the art andcommercially available; such as a ground silica sold under the nameMIN—U-SIL by U.S. Silica of Berkeley Springs, W.Va. Suitableprecipitated calcium carbonates included Winnofil™ SPM from Solvay andUltrapflex™ and Ultrapflex™ 100 from SMI. Examples of suitable fillersare disclosed in U.S. Pat. No. 9,156,948.

Starting Material L)—Spacer

The adhesive composition described above may optionally further compriseL) a spacer. Spacers can comprise organic particles, inorganicparticles, or a combination thereof. Spacers can be thermallyconductive, electrically conductive, or both. Spacers can have a desiredparticle size, for example, particle size may range from 25 μm to 125μm. Spacers can comprise monodisperse beads, such as glass or polymer(e.g., polystyrene) beads. Spacers can comprise thermally conductivefillers such as alumina, aluminum nitride, atomized metal powders, boronnitride, copper, and silver. The amount of spacer depends on variousfactors including the particle size distribution, pressure to be appliedduring use of the composition prepared by mixing the parts, or the curedproduct prepared therefrom, temperature during use, and desiredthickness of the mixed composition or the cured product preparedtherefrom. However, the composition may contain an amount of spacer of0.05% to 2%, alternatively 0.1% to 1% based on combined weights of allstarting materials in the composition.

Starting Material M)—Acid Scavenger

The composition described above may optionally further comprise M) anacid scavenger. Suitable acid scavengers include various inorganic andorganic compounds that are basic in nature, such as magnesium oxide,calcium oxide, and combinations thereof. The composition may comprise 0%to 10% of acid scavenger based on the combined weights of all startingmaterials in the composition.

Starting Material N)—Silanol Functional Polydiorganosiloxane

The composition described above may optionally further comprise N) asilanol functional polydiorganosiloxane. Starting material N) maycomprise a polydiorganosiloxane of the formula HOR²² ₂SiO(R²²₂Si_(O))_(eee)((HO)R²²SiO)_(fff)SiR²² ₂OH, the formulaR₃SiO(R₂SiO)_(ggg)((HO)RSiO)_(hhh)SiR₃, or a combination thereof, whereR²² is as described above. Subscript eee may be 0 or a positive number.Alternatively, subscript eee has an average value of at least 2.Alternatively subscript eee may be 2 to 2000. Subscript fff may be 0 ora positive number. Alternatively, subscript fff may have an averagevalue of 0 to 2000. Subscript ggg may be 0 or a positive number.Alternatively, subscript ggg may have an average value of 0 to 2000.Subscript hhh has an average value of at least 2. Alternativelysubscript hhh may have an average value ranging from 2 to 2000.

Starting material N) may comprise a polydiorganosiloxane such as

i) hydroxy-terminated polydimethylsiloxane,ii) hydroxy-terminated poly(dimethylsiloxane/methylphenylsiloxane),iii) trimethylsiloxy-terminatedpoly(dimethylsiloxane/methylhydroxysiloxane), andiv) a combination of two or more of i), ii) and iii).

Hydroxyl-endblocked polydiorganosiloxanes suitable for use as startingmaterial N) may be prepared by methods known in the art, such ashydrolysis and condensation of the corresponding organohalosilanes orequilibration of cyclic polydiorganosiloxanes. When added to theadhesive composition, starting material N) may be present in an amountof 0.1% to 20%, alternatively 0.1% to 10%, and alternatively 0.1% to 5%based on combined weights of all starting materials in the adhesivecomposition.

Starting Material O)—Optical Brightener

The adhesive composition described above may optionally further comprisestarting material O), an optical brightener. Suitable opticalbrighteners are commercially available, such as2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole), commerciallyavailable as TINOPAL OB. When added to the composition, the opticalbrightener may be present in an amount of 0.1% to 2% based on combinedweights of all starting materials in the adhesive composition.

Starting Material P)—Chain Transfer Agent

The adhesive composition described above may optionally further comprisea P) chain transfer agent. When added to the adhesive composition, thechain transfer agent may be present in an amount of 0.01% to 5%,alternatively 0.01% to 2%, and alternatively 0.1 to 2%, based oncombined weights of all starting materials in the composition.

Starting Material Q)—(Meth)acrylate Monomer

The adhesive composition described above may optionally further comprisestarting material Q), a (meth)acrylate monomer. The (meth)acrylatemonomer is exemplified by methylacrylate, butylacrylate,2-ethylhexylacrylate, isobornylacrylate, terahydrofurfuryl acrylate,cyclohexylmethylacrylate methyl methacrylate, butylmethacrylate,2-ethylhexylmethacrylate, isobornylmethacrylate, terahydrofurfurylmethacrylate, and cyclohexylmethylmethacrylate. When added to theadhesive composition, the (meth)acrylate monomer may be present in anamount of 0.1% to 35%, alternatively 0.1% to 25%, alternatively 0.1 to15%, and alternatively 0.1% to 10%, based on combined weights of allstarting materials in the adhesive composition.

Starting Material R)—Poly-Alkoxy Terminated Polydiorganosiloxane

Starting material R) is a poly-alkoxy terminated polydiorganosiloxane,in addition to any that would be prepared via preparation of startingmaterial B), described above. Starting material R) may be a poly-alkoxyterminated polydiorganosiloxane prepared as described above for startingmaterial B), except without including the siloxane resin. Alternatively,starting material R) may be a poly-alkoxy terminatedpolydiorganosiloxane prepared via a platinum catalyzed hydrosilylationreaction.

Starting Material S)—Colorant

The adhesive composition described above may optionally further comprisestarting material S), a colorant. The colorant may be a dye or pigment,such as carbon black.

When selecting starting materials for the adhesive composition describedabove, there may be overlap between types of starting materials becausecertain starting materials described herein may have more than onefunction. For example, certain alkoxysilanes may be useful ascrosslinkers and/or adhesion promoters and/or drying agents. Certainparticulates may be useful as fillers and spacers. When addingadditional starting materials to the adhesive composition, theadditional starting materials are distinct from one another.

Method for Preparing the Adhesive Composition

The adhesive composition described above may be prepared by 1) combiningstarting materials B) i) the organosiloxane resin and B) ii) thepolydiorganosiloxane to form B) the resin polymer blend (RPB). Solventmay optionally be used to homogenize the RPB. One or more of thestarting materials, such as the organosiloxane resin may be dissolved ordispersed in a solvent, such as those described above, e.g., an aromatichydrocarbon such as benzene, toluene or xylene. The amount of solventmay be 0 to 60%, alternatively 10% to 50%, and alternatively 20% to 40%based on combined weights of all starting materials in the adhesivecomposition. Starting materials B) iii) and B) iv) as described above,may be combined with the RPB to form a converted RPB. The method mayfurther comprise: 2) combining the converted RPB and starting materialsA), C), and D) by any convenient means, such as mixing. One or moreadditional starting materials E) to S) as described above may be addedduring step 1), step 2) or both. The starting materials may be combinedat 20° C. to 150° C. The method may further comprise heating thestarting materials at a temperature of 50° C. to 150° C., alternatively60° C. to 120° C. in step 1), step 2) or both. The pressure is notcritical; the method may be performed at ambient pressure.

Release Coating Composition

Alternatively, the curable composition may be a release coatingcomposition. The release coating composition comprises:

(i) the a) polyfunctional organohydrogensiloxane, or product of themethod described above said product comprising the polyfunctionalorganohydrogensiloxane, as described above;(ii) a polyorganosiloxane having an average, per molecule, of at leasttwo silicon bonded aliphatically unsaturated groups capable ofundergoing hydrosilylation reaction,(iii) a hydrosilylation reaction catalyst, and(iv) a hydrosilylation reaction inhibitor.

Starting Material (ii) Polyorganosiloxane Having AliphaticallyUnsaturated Groups

Starting material (ii) in the release coating composition is apolyorganosiloxane having an average, per molecule, of at least twosilicon bonded aliphatically unsaturated groups capable of undergoinghydrosilylation reaction; alternatively a polyorganosiloxane having anaverage, per molecule, of at least two silicon bonded groups havingterminal aliphatic unsaturation. This polyorganosiloxane may be linear,branched, partly branched, cyclic, resinous (i.e., have athree-dimensional network), or may comprise a combination of differentstructures. The polyorganosiloxane may have average formula: R¹³_(a)SiO_((4-a)/2), where each R¹³ is independently selected from amonovalent hydrocarbon group or a monovalent halogenated hydrocarbongroup, with the proviso that in each molecule, at least two of R¹³include aliphatic unsaturation, and where subscript a is selected suchthat 0<a≤3.2. Suitable monovalent hydrocarbon groups and monovalenthalogenated hydrocarbon groups for R¹³ are as described above for R¹.The average formula above for the polyorganosiloxane may bealternatively written as (R¹³ ₃SiO_(1/2))_(b)(R¹³₂SiO_(2/2))_(c)(R¹³SiO_(3/2))_(d)(SiO_(4/2))_(e), where R¹³ is definedabove, and subscripts b, c, d, and e are each independently from ≥0 to≤1, with the proviso that a quantity (b+c+d+e)=1. One of skill in theart understands how such M, D, T, and Q units and their molar fractionsinfluence subscript a in the average formula above. T units (indicatedby subscript d), Q units (indicated by subscript e) or both, aretypically present in polyorganosiloxane resins, whereas D units,indicated by subscript c, are typically present in polyorganosiloxanepolymers (and may also be present in polyorganosiloxane resins orbranched polyorganosiloxanes).

Alternatively, starting material (i) may comprise a polyorganosiloxanethat is substantially linear, alternatively is linear. The substantiallylinear polyorganosiloxane may have the average formula: R¹³_(a′)SiO_((4-a′)/2), where each R¹³ and is as defined above, and wheresubscript a′ is selected such that 1.9≤a′≤2.2.

At RT, the substantially linear polyorganosiloxane may be a flowableliquid or may have the form of an uncured rubber. The substantiallylinear polyorganosiloxane may have a viscosity of 10 mPa·s to 30,000,000mPa·s, alternatively 10 mPa·s to 10,000 mPa·s, alternatively 100 mPa·sto 1,000,000 mPa·s, and alternatively 100 mPa·s to 100,000 mPa·s at 25°C. Viscosity may be measured at RT via a Brookfield LV DV-E viscometerwith a spindle selected as appropriate to the viscosity of thesubstantially linear polyorganosiloxane, i.e., RV-1 to RV-7.

Alternatively, when (ii) the polyorganosiloxane is substantially linearor linear, the polyorganosiloxane may have the average unit formula:(R¹⁰R⁹ ₂SiO_(1/2))_(aa))(R¹⁰R⁹SiO_(2/2))_(bb)(R¹⁰ ₂SiO_(2/2))_(cc)(R⁹₃SiO_(1/2))_(dd), where each R⁹ is an independently selected monovalenthydrocarbon group that is free of aliphatic unsaturation or a monovalenthalogenated hydrocarbon group that is free of aliphatic unsaturation;each R¹⁰ is independently selected from the group consisting of alkenyland alkynyl; subscript aa is 0, 1, or 2, subscript bb is 0 or more,subscript cc is 1 or more, subscript dd is 0, 1, or 2, with the provisosthat a quantity (aa+dd)≥2, and (aa+dd)=2, with the proviso that aquantity (aa+bb+cc+dd) is 3 to 2,000. Alternatively, subscript cc≥0.Alternatively, subscript bb≥2. Alternatively, the quantity (aa+dd) is 2to 10, alternatively 2 to 8, and alternatively 2 to 6. Alternatively,subscript cc is 0 to 1,000, alternatively 1 to 500, and alternatively 1to 200. Alternatively, subscript bb is 2 to 500, alternatively 2 to 200,and alternatively 2 to 100.

The monovalent hydrocarbon group for R⁹ is exemplified by an alkyl groupof 1 to 6 carbon atoms, an aryl group of 6 to 10 carbon atoms, ahalogenated alkyl group of 1 to 6 carbon atoms, a halogenated aryl groupof 6 to 10 carbon atoms, an aralkyl group of 7 to 12 carbon atoms or ahalogenated aralkyl group of 7 to 12 carbon atoms, where alkyl, aryl,and halogenated alkyl are as described herein. Alternatively, each R⁹ isindependently a monovalent hydrocarbon group free of aliphaticunsaturation. Alternatively, each R⁹ is an alkyl group. Alternatively,each R⁹ is independently methyl, ethyl or propyl. Each instance of R⁹may be the same or different. Alternatively, each R⁹ is a methyl group.

The aliphatically unsaturated monovalent hydrocarbon group for R¹⁰ iscapable of undergoing hydrosilylation reaction. Suitable aliphaticallyunsaturated hydrocarbon groups for R¹⁰ are exemplified by an alkenylgroup as defined herein and exemplified by vinyl, allyl, butenyl, andhexenyl; and alkynyl groups as defined herein and exemplified by ethynyland propynyl. Alternatively, each R¹⁰ may be vinyl or hexenyl.Alternatively, each R¹⁰ is a vinyl group. The subscripts in the unitformula for (ii-I) above may have values sufficient that the alkenyl oralkynyl content of the branched siloxane for (ii-I) may be 0.1% to 1%,alternatively 0.2% to 0.5%, based on the weight of branched siloxane(ii-1).

When (ii) the polyorganosiloxane is substantially linear, alternativelyis linear, the at least two aliphatically unsaturated groups may bebonded to silicon atoms in pendent positions, terminal positions, or inboth pendent and terminal locations. As a specific example of thepolyorganosiloxane having pendant silicon-bonded aliphaticallyunsaturated groups, starting material A) may have the average unitformula:[(CH₃)₃SiO_(1/2)]₂[(CH₃)₂SiO_(2/2)]_(cc)[(CH₃)ViSiO_(2/2)]_(bb), wheresubscripts bb and cc are defined above, and Vi indicates a vinyl group.With regard to this average formula, any methyl group may be replacedwith a different monovalent hydrocarbon group (such as alkyl or aryl),and any vinyl group may be replaced with a different aliphaticallyunsaturated monovalent hydrocarbon group (such as allyl or hexenyl).Alternatively, as a specific example of the polyorganosiloxane having anaverage, per molecule, of at least two silicon-bonded aliphaticallyunsaturated groups, starting material (ii) may have the average formula:Vi(CH₃)₂SiO[(CH₃)₂SiO]_(cc)Si(CH₃)₂Vi, where subscript cc and Vi aredefined above. The dimethyl polysiloxane terminated with silicon-bondedvinyl groups may be used alone or in combination with the dimethyl,methyl-vinyl polysiloxane disclosed immediately above. With regard tothis average formula, any methyl group may be replaced with a differentmonovalent hydrocarbon group, and any vinyl group may be replaced withany terminally aliphatically unsaturated monovalent hydrocarbon group.Because the at least two silicon-bonded aliphatically unsaturated groupsmay be both pendent and terminal, (ii) the polyorganosiloxane mayalternatively have the average unit formula:[Vi(CH₃)₂SiO_(1/2)]₂[(CH₃)₂SiO_(2/2)]_(cc)[(CH₃)ViSiO_(2/2)]_(bb), wheresubscripts bb and cc and Vi are defined above.

The substantially linear polyorganosiloxane can be exemplified by adimethylpolysiloxane capped at both molecular terminals withdimethylvinylsiloxy groups, a methylphenylpolysiloxane capped at bothmolecular terminals with dimethylvinylsiloxy groups, a copolymer of amethylphenylsiloxane and dimethylsiloxane capped at both molecularterminals with dimethylvinylsiloxy groups, a copolymer of amethylvinylsiloxane and a methylphenylsiloxane capped at both molecularterminals with dimethylvinylsiloxy groups, a copolymer of amethylvinylsiloxane and diphenylsiloxane capped at both molecularterminals with dimethylvinylsiloxy groups, a copolymer of amethylvinylsiloxane, methylphenylsiloxane, and dimethylsiloxane cappedat both molecular terminals with dimethylvinylsiloxy groups, a copolymerof a methylvinylsiloxane and a methylphenylsiloxane capped at bothmolecular terminals with trimethylsiloxy groups, a copolymer of amethylvinylsiloxane and diphenylsiloxane capped at both molecularterminals with trimethylsiloxy groups, and a copolymer of amethylvinylsiloxane, methylphenylsiloxane, and a dimethylsiloxane cappedat both molecular terminals with trimethylsiloxy groups.

Alternatively, starting material (ii) may comprise a substantiallylinear, alternatively linear, polyorganosiloxane selected from the groupconsisting of:

i) dimethylvinylsiloxy-terminated polydimethylsiloxane,ii) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylvinylsiloxane),iii) dimethylvinylsiloxy-terminated polymethylvinylsiloxane,iv) trimethylsiloxy-terminatedpoly(dimethylsiloxane/methylvinylsiloxane),v) trimethylsiloxy-terminated polymethylvinylsiloxane,vi) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylvinylsiloxane),vii) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylphenylsiloxane),viii) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/diphenylsiloxane),ix) phenyl,methyl,vinyl-siloxy-terminated polydimethylsiloxane,x) dimethylhexenylsiloxy-terminated polydimethylsiloxane,xi) dimethylhexenylsiloxy-terminatedpoly(dimethylsiloxane/methylhexenylsiloxane),xii) dimethylhexenylsiloxy-terminated polymethylhexenylsiloxane,xiii) trimethylsiloxy-terminatedpoly(dimethylsiloxane/methylhexenylsiloxane),xiv) trimethylsiloxy-terminated polymethylhexenylsiloxanexv) dimethylhexenyl-siloxy terminatedpoly(dimethylsiloxane/methylhexenylsiloxane),xvi) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylhexenylsiloxane), andxvii) a combination thereof.

Alternatively, A) the polyorganosiloxane may be a resinouspolyorganosiloxane. The resinous polyorganosiloxane may have the averageformula: R¹³ _(a″)SiO_((4-a″)/2), where each R¹³ is as defined above,and where subscript a″ is selected such that 0.5≤a″≤1.7.

The resinous polyorganosiloxane has a branched or a three dimensionalnetwork molecular structure. At 25° C., the resinous polyorganosiloxanemay be in a liquid or in a solid form. Alternatively, the resinouspolyorganosiloxane may be exemplified by a polyorganosiloxane thatcomprises only T units, a polyorganosiloxane that comprises T units incombination with other siloxy units (e.g., M, D, and/or Q siloxy units),or a polyorganosiloxane comprising Q units in combination with othersiloxy units (i.e., M, D, and/or T siloxy units). Typically, theresinous polyorganosiloxane comprises T and/or Q units. Specific exampleof the resinous polyorganosiloxane include a vinyl-terminatedsilsesquioxane and a vinyl terminated MDQ resin.

Alternatively, starting material (ii) may comprise (ii-I) a branchedsiloxane, (ii-II) a silsesquioxane or both (ii-I) and (ii-II). Startingmaterials (ii-I) and (ii-II) may be particularly useful when thecomposition will be used for release coating applications.

Starting material (ii) may be a combination of the (ii-I) branchedsiloxane and (ii-II) the silsesquioxane. The combination may be aphysical blend or mixture. The branched siloxane and the silsesquioxaneare present in amounts relative to one another such that the amount of(ii-I) the branched siloxane and the amount of (ii-II) thesilsesquioxane combined total 100 weight parts, based on combinedweights of all starting materials in the release coating composition.The branched siloxane may be present in an amount of 50 to 100 parts byweight, and the silsesquioxane may be present in an amount of 0 to 50parts by weight. Alternatively, the branched siloxane may be present inan amount 50 to 90 parts by weight and the silsesquioxane may be presentin an amount of 10 to 50 parts by weight. Alternatively, the branchedsiloxane may be present in an amount of 50 to 80 parts by weight and thesilsesquioxane may be present in an amount of 20 to 50 parts by weight.Alternatively, the branched siloxane may be present in an amount of 50to 76 parts by weight and the silsesquioxane may be present in an amountof 24 to 50 parts by weight. Alternatively, the branched siloxane may bepresent in an amount of 50 to 70 parts by weight and the silsesquioxanemay be present in an amount of 30 to 50 parts by weight. Without wishingto be bound by theory, it is thought that if the amount ofsilsesquioxane (ii-II) exceeds 50 weight parts, per 100 weight parts thecombined amounts of (ii-I) the branched siloxane and (ii-II) thesilsesquioxane, the release coating formed from the composition maysuffer from the drawback of migration, where silsesquioxane can migrateand contaminate an adherend such as a pressure sensitive adhesive incontact with the release coating.

Starting material (ii-I) the branched siloxane may have unit formula(ii-I): (R⁹ ₃SiO_(1/2))_(p)(R¹⁰R⁹ ₂SiO_(1/2))_(q)(R⁹₂SiO_(2/2))_(r)(SiO_(4/2))_(s), where each R⁹ is independently amonovalent hydrocarbon group free of aliphatic unsaturation or amonovalent halogenated hydrocarbon group free of aliphatic unsaturationand each R¹⁰ is an alkenyl group or an alkynyl group, both of which areas described above, subscript p≥0, subscript q>0, 15≥r≥995, andsubscript s is >0.

In the unit formula for (ii-I), subscript p 0. Subscript q>0.Alternatively, subscript q≥3. Subscript r is 15 to 995. Subscript sis >0. Alternatively, subscript s≥1. Alternatively, for subscript p:22≥p≥0; alternatively 20≥p≥0; alternatively 15≥p≥0; alternatively10≥p≥0; and alternatively 5≥p≥0. Alternatively, for subscript q: 22≥q>0;alternatively 22≥q≥4; alternatively 20≥q>0; alternatively 15≥q>1;alternatively 10≥q≥2; and alternatively 15≥q≥4. Alternatively, forsubscript r: 800≥r≥15; and alternatively 400≥r≥15. Alternatively, forsubscript s: 10≥s>0; alternatively, 10≥s≥1; alternatively 5≥s>0; andalternatively s=1. Alternatively, subscript s is 1 or 2. Alternatively,when subscript s=1, subscript p may be 0 and subscript q may be 4.

The branched siloxane may contain at least two polydiorganosiloxanechains of formula (R⁹ ₂SiO_(2/2))_(m), where each subscript m isindependently 2 to 100. Alternatively, the branched siloxane maycomprise at least one unit of formula (SiO_(4/2)) bonded to fourpolydiorganosiloxane chains of formula (R⁹ ₂SiO_(2/2))_(o), where eachsubscript o is independently 1 to 100. Alternatively, the branchedsiloxane may have formula:

where subscript u is 0 or 1, each subscript t is independently 0 to 995,alternatively 15 to 995, and alternatively 0 to 100; each R¹¹ is anindependently selected monovalent hydrocarbon group, each R⁹ is anindependently selected monovalent hydrocarbon group that is free ofaliphatic unsaturation or a monovalent halogenated hydrocarbon groupthat is free of aliphatic unsaturation as described above, and each R¹⁰is independently selected from the group consisting of alkenyl andalkynyl as described above. Suitable branched siloxanes for startingmaterial (ii-I) are exemplified by those disclosed in U.S. Pat. No.6,806,339 and U.S. Patent Publication 2007/0289495.

The silsesquioxane has unit formula (ii-II): (R⁹ ₃SiO_(1/2))_(i)(R¹⁰R⁹₂SiO_(1/2))_(f)(R⁹ ₂SiO_(2/2))_(g)(R⁹SiO_(3/2))_(h), where R⁹ and R¹⁰are as described above, subscript i≥0, subscript f>0, subscript g is 15to 995, and subscript h>0. Subscript i may be 0 to 10. Alternatively,for subscript i: 12≥i≥0; alternatively 10≥i≥0; alternatively 7≥i≥0;alternatively 5≥i≥0; and alternatively 3≥i≥0.

Alternatively, subscript f≥1. Alternatively, subscript f≥3.Alternatively, for subscript f: f≥0; alternatively 12≥f≥3; alternatively10≥f>0; alternatively 7≥f>1; alternatively 5≥f≥2; and alternatively7≥f≥3. Alternatively, for subscript g: 800≥g≥15; and alternatively400≥g≥15. Alternatively, subscript h≥1. Alternatively, subscript h is 1to 10. Alternatively, for subscript h: 10≥h>0; alternatively 5≥h>0; andalternatively h=1. Alternatively, subscript h is 1 to 10, alternativelysubscript h is 1 or 2. Alternatively, when subscript h=1, then subscriptf may be 3 and subscript i may be 0. The values for subscript f may besufficient to provide the silsesquioxane of unit formula (ii-II) with analkenyl content of 0.1% to 1%, alternatively 0.2% to 0.6%, based on theweight of the silsesquioxane. Suitable silsesquioxanes for startingmaterial (ii) are exemplified by those disclosed in U.S. Pat. No.4,374,967.

Starting material (ii) may comprise a combination or two or moredifferent polyorganosiloxanes that differ in at least one property suchas structure, molecular weight, monovalent groups bonded to siliconatoms and content of aliphatically unsaturated groups. The releasecoating composition may contain 60% to 98%, alternatively 60% to 95% ofstarting material (ii), based on combined weights of all startingmaterials in the release coating composition.

Starting Material (iii) Hydrosilylation Reaction Catalyst

The hydrosilylation reaction catalyst used as starting material (iii) inthe release coating composition may be as described and exemplifiedabove for starting material b). Alternatively, the hydrosilylationreaction catalyst for use in the release coating composition may beselected from the group consisting of Karstedt's catalyst and Ashby'scatalyst. The (iii) hydrosilylation-reaction catalyst is present in therelease coating composition in a catalytic amount, i.e., an amount orquantity sufficient to promote curing thereof at desired conditions. Thecatalytic amount of the (iii) hydrosilylation reaction catalyst maybe >0.01 ppm to 10,000 ppm; alternatively >1,000 ppm to 5,000 ppm.Alternatively, the typical catalytic amount of (iii) the hydrosilylationreaction catalyst is 0.1 ppm to 5,000 ppm, alternatively 1 ppm to 2,000ppm, alternatively >0 to 1,000 ppm. Alternatively, the catalytic amountof the (iii) hydrosilylation reaction catalyst may be 0.01 ppm to 1,000ppm, alternatively 0.01 ppm to 100 ppm, alternatively 20 ppm to 200 ppm,and alternatively 0.01 ppm to 50 ppm of platinum group metal; based oncombined weights of all starting materials in the release coatingcomposition.

Starting Material (iv) Hydrosilylation Reaction Inhibitor

Starting material (iv) is an inhibitor that may be used for altering thereaction rate of the release coating composition, as compared to acomposition containing the same starting materials but with theinhibitor omitted. Inhibitors for hydrosilylation curable compositionsare exemplified by acetylenic alcohols such as methyl butynol, ethynylcyclohexanol, dimethyl hexynol, and 3,5-dimethyl-1-hexyn-3-ol,1-butyn-3-ol, 1-propyn-3-ol, 2-methyl-3-butyn-2-ol,3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3-phenyl-1-butyn-3-ol,4-ethyl-1-octyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and1-ethynyl-1-cyclohexanol, and a combination thereof;cycloalkenylsiloxanes such as methylvinylcyclosiloxanes exemplified by1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane,1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, and acombination thereof; ene-yne compounds such as 3-methyl-3-penten-1-yne,3,5-dimethyl-3-hexen-1-yne; triazoles such as benzotriazole; phosphines;mercaptans; hydrazines; amines, such as tetramethyl ethylenediamine,dialkyl fumarates, dialkenyl fumarates, dialkoxyalkyl fumarates,maleates such as diallyl maleate; nitriles; ethers; carbon monoxide;alkenes such as cyclo-octadiene, divinyltetramethyldisiloxane; alcoholssuch as benzyl alcohol; and a combination thereof. Alternatively, thehydrosilylation reaction inhibitor may be selected from the groupconsisting of acetylenic alcohols (e.g., 1-ethynyl-1-cyclohexanol) andmaleates (e.g., diallyl maleate, bis maleate, or n-propyl maleate) and acombination of two or more thereof.

Alternatively, starting material (iv) in the composition may be asilylated acetylenic compound. Without wishing to be bound by theory, itis thought that adding a silylated acetylenic compound reduces yellowingof the reaction product prepared from hydrosilylation reaction of thecomposition as compared to a reaction product from hydrosilylation of acomposition that does not contain a silylated acetylenic compound orthat contains an organic acetylenic alcohol inhibitor, such as thosedescribed above.

The silylated acetylenic compound is exemplified by(3-methyl-1-butyn-3-oxy)trimethylsilane,((1,1-dimethyl-2-propynyl)oxy)trimethylsilane,bis(3-methyl-1-butyn-3-oxy)dimethylsilane,bis(3-methyl-1-butyn-3-oxy)silanemethylvinylsilane,bis((1,1-dimethyl-2-propynyl)oxy)dimethylsilane,methyl(tris(1,1-dimethyl-2-propynyloxy))silane,methyl(tris(3-methyl-1-butyn-3-oxy))silane,(3-methyl-1-butyn-3-oxy)dimethylphenylsilane,(3-methyl-1-butyn-3-oxy)dimethylhexenylsilane,(3-methyl-1-butyn-3-oxy)triethylsilane,bis(3-methyl-1-butyn-3-oxy)methyltrifluoropropylsilane,(3,5-dimethyl-1-hexyn-3-oxy)trimethylsilane,(3-phenyl-1-butyn-3-oxy)diphenylmethylsilane,(3-phenyl-1-butyn-3-oxy)dimethylphenylsilane,(3-phenyl-1-butyn-3-oxy)dimethylvinylsilane,(3-phenyl-1-butyn-3-oxy)dimethylhexenylsilane,(cyclohexyl-1-ethyn-1-oxy)dimethylhexenylsilane,(cyclohexyl-1-ethyn-1-oxy)dimethylvinylsilane,(cyclohexyl-1-ethyn-1-oxy)diphenylmethylsilane,(cyclohexyl-1-ethyn-1-oxy)trimethylsilane, and combinations thereof.Alternatively, Starting material (iv) is exemplified bymethyl(tris(1,1-dimethyl-2-propynyloxy))silane,((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, or a combination thereof.The silylated acetylenic compound useful as starting material (iv) maybe prepared by methods known in the art, such as silylating anacetylenic alcohol described above by reacting it with a chlorosilane inthe presence of an acid receptor.

The amount of inhibitor added to the release coating composition willdepend on various factors including the desired pot life of thecomposition, whether the composition will be a one part composition or amultiple part composition, the particular inhibitor used, and theselection and amount of starting materials (i) and (ii). However, whenpresent, the amount of inhibitor may be 0% to 1%, alternatively 0% to5%, alternatively 0.001% to 1%, alternatively 0.01% to 0.5%, andalternatively 0.0025% to 0.025%, based on combined weights of allstarting materials in the composition.

Additional Starting Materials

The release coating composition may optionally further comprise one ormore additional starting materials selected from: (v) an anchorageadditive, (vi) an anti-mist additive, (vii) a release modifier, (viii) asubstantially linear or linear polyorganohydrogensiloxane, and (ix) asolvent, such as that described above for starting material D).

(v) Anchorage Additive

Starting material (v) is an anchorage additive. Suitable anchorageadditives are exemplified by a reaction product of a vinyl alkoxysilaneand an epoxy-functional alkoxysilane; a reaction product of a vinylacetoxysilane and epoxy-functional alkoxysilane; and a combination(e.g., physical blend and/or a reaction product) of a polyorganosiloxanehaving at least one aliphatically unsaturated hydrocarbon group and atleast one hydrolyzable group per molecule and an epoxy-functionalalkoxysilane (e.g., a combination of a hydroxy-terminated, vinylfunctional polydimethylsiloxane with glycidoxypropyltrimethoxysilane).Alternatively, the anchorage additive may comprise a polyorganosilicateresin. Suitable anchorage additives and methods for their preparationare disclosed, for example, in U.S. Pat. No. 9,562,149; U.S. PatentApplication Publication Numbers 2003/0088042, 2004/0254274, and2005/0038188; and European Patent 0 556 023. The exact amount ofanchorage additive depends on various factors including the type ofsubstrate and whether a primer is used, however, the amount of anchorageadditive in the release coating composition may be 0 to 2 parts byweight, per 100 parts by weight of starting material (ii).Alternatively, the amount of anchorage additive, may be 0.01 to 2 partsby weight, per 100 parts by weight of starting material (ii).

(vi) Anti-Mist Additive

Starting material (vi) is an anti-mist additive that may be added to therelease coating composition to reduce or suppress silicone mistformation in coating processes, particularly with high speed coatingequipment. The anti-mist additive may be a reaction product of anorganohydrogensilicon compound, an oxyalkylene compound or anorganoalkenylsiloxane with at least three silicon bonded alkenyl groupsper molecule, and a suitable catalyst. Suitable anti-mist additives aredisclosed, for example, in U.S. Patent Application 2011/0287267; U.S.Pat. Nos. 8,722,153; 6,586,535; and 5,625,023.

The amount of anti-mist additive will depend on various factorsincluding the amount and type of other starting materials selected forthe release coating composition. However, the amount of anti-mistadditive may be 0% to 10%, alternatively 0.1% to 3%, based on combinedweights of all starting materials in the release coating composition.

(vii) Release Modifier

Starting material (vii) is a release modifier that may be added to therelease coating composition to control (decrease) the level of releaseforce (the adhesive force between the release coating and an adherendthereto, such as a label including a pressure sensitive adhesive).Release coating compositions having the required release force can beformulated from a modifier-free release coating composition by adjustingthe level of modifier. Examples of suitable release modifiers includetrimethylsiloxy-terminated dimethyl, phenylmethylsiloxanes.Alternatively, the release modifier may be a condensation reactionproduct of an organopolysiloxane resin having hydroxyl or alkoxy groupsand a diorganopolysiloxane with at least one hydroxyl or hydrolyzablegroup. If used, a release modifier can, for example, be used at 0 to 85parts by weight, alternatively 25 to 85 parts, per 100 parts of startingmaterial (ii). Examples of suitable release modifiers are disclosed, forexample, in U.S. Pat. No. 8,933,177 and U.S. Patent ApplicationPublication 2016/0053056.

(viii) Linear Polyorganohydrogensiloxane

Starting material (viii) is a substantially linear, alternativelylinear, polyorganohydrogensiloxane distinct from starting material (i),which may be added as an additional crosslinker to the release coatingcomposition. The substantially linear or linearpolyorganohydrogensiloxane has unit formula: (HR¹²₂SiO_(1/2))_(v′)(HR¹²SiO_(2/2))_(w′)(R¹² ₂SiO_(2/2))_(x′)(R¹²₃SiO_(1/2))_(y′), where each R¹² is an independently selected monovalenthydrocarbon group, subscript v′ is 0, 1, or 2, subscript w′ is 1 ormore, subscript x′ is 0 or more, subscript y′ is 0, 1, or 2, with theprovisos that a quantity (v′+y′)=2, and a quantity (v′+w′)≥3. Themonovalent hydrocarbon group for R¹² may be as described above for themonovalent hydrocarbon group for R¹. A quantity (v′+w′+x′+y′) may be 2to 1,000. The polyorganohydrogensiloxane is exemplified by:

i) dimethylhydrogensiloxy-terminatedpoly(dimethyl/methylhydrogen)siloxane copolymer,ii) dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane,iii) trimethylsiloxy-terminated poly(dimethyl/methylhydrogen)siloxanecopolymer, andiv) trimethylsiloxy-terminated polymethylhydrogensiloxane, andv) a combination of two or more of i), ii), iii), iv), and v). Suitablepolyorganohydrogensiloxanes are commercially available from DowSilicones Corporation of Midland, Mich., USA.

(ix) Solvent

Starting material (x) is a solvent. Suitable solvents include thehydrocarbons described above as starting material D) in the method formaking the polyfunctional organohydrogensiloxane. Alternatively, thesolvent may be selected from polyalkylsiloxanes, alcohols, ketones,glycol ethers, tetrahydrofuran, mineral spirits, naphtha,tetrahydrofuran, mineral spirits, or a combination thereof.Polyalkylsiloxanes with suitable vapor pressures may be used as thesolvent, and these include hexamethyldisiloxane, octamethyltrisiloxane,hexamethylcyclotrisiloxane and other low molecular weightpolyalkylsiloxanes, such as 0.5 to 1.5 cSt DOWSIL™ 200 Fluids andDOWSIL™ OS FLUIDS, which are commercially available from Dow SiliconesCorporation of Midland, Mich., U.S.A.

Alternatively, starting material (x) may comprise an organic solvent.The organic solvent can be an alcohol such as methanol, ethanol,isopropanol, butanol, or n-propanol; a ketone such as acetone,methylethyl ketone, or methyl isobutyl ketone; an aromatic hydrocarbonsuch as benzene, toluene, or xylene; an aliphatic hydrocarbon such asheptane, hexane, or octane; a glycol ether such as propylene glycolmethyl ether, dipropylene glycol methyl ether, propylene glycol n-butylether, propylene glycol n-propyl ether, or ethylene glycol n-butylether, tetrahydrofuran; mineral spirits; naphtha; or a combinationthereof.

The amount of solvent will depend on various factors including the typeof solvent selected and the amount and type of other starting materialsselected for the release coating composition. However, the amount ofsolvent may be 0% to 99%, alternatively 2% to 50%, based on the weightof all starting materials in the release coating composition. Thesolvent may be added during preparation of the release coatingcomposition, for example, to aid mixing and delivery. All or a portionof the solvent may optionally be removed after the release coatingcomposition is prepared.

Other optional starting materials which may also be added to releasecoating compositions described herein include, for example, reactivediluents, fragrances, preservatives colorants, and fillers, for example,silica, quartz or chalk.

When selecting starting materials for the release coating composition(and other curable compositions described herein), there may be overlapbetween types of starting materials because certain starting materialsdescribed herein may have more than one function. Certain particulatesmay be useful as fillers and as colorants such as pigments, and even asflame retardants, e.g., carbon black. When adding additional startingmaterials to the release coating composition, the additional startingmaterials are distinct from starting materials (i) to (iv) and from oneanother.

Alternatively, the release coating may be free of particulates orcontains only a limited amount of particulate (e.g., filler and/orpigment), such as 0 to 30% by weight of the release coating composition.Particulates can agglomerate or otherwise stick to the coater equipmentused to apply the release coating. They can hinder optical properties,for example transparency, of the release coating and of the releaseliner formed therewith, if optical transparency is desired. Theparticulates may be prejudicial to the adherence of an adherend.

Alternatively, the release coating composition of the invention may befree from fluoroorganosilicone compounds. It is believed that, duringthe cure, a fluorocompound, because of its low surface tension, mayrapidly migrate to the interface of a coating composition and asubstrate, for example a polyorganosiloxane release coatingcomposition/PET film interface, and prevent adherence of the releasecoating (prepared by curing the release coating composition) to thesubstrate by making a fluorine containing barrier. By making a barrier,the fluorocompound may prevents any starting material from reacting atthe interface. Moreover, fluorosilicone compounds are usually expensive.

The release composition may be prepared by combining starting materialscomprising (i), (ii), (iii) and (iv), described above, along with anyoptional additional starting materials, in any order of addition,optionally with a master batch, and optionally under shear.

Method for Coating a Substrate

A method of preparing a coated substrate with the curable compositioncomprises disposing the curable composition on the substrate. The methodfurther comprises curing the curable composition on the substrate.Curing may be performed by heating at an elevated temperature, e.g., 50°C. to 180° C., alternatively 50° C. to 120° C., and alternatively 50° C.to 90° C. to give the coated substrate. One skilled in the art would beable to select an appropriate temperature depending on various factorsincluding the selection of optional starting materials in the curablecomposition and the substrate material of construction.

The curable composition may be disposed or dispensed on the substrate inany suitable manner. Typically, the curable composition is applied inwet form via a wet coating technique. The curable composition may beapplied by i) spin coating; ii) brush coating; iii) drop coating; iv)spray coating; v) dip coating; vi) roll coating; vii) flow coating;viii) slot coating; ix) gravure coating; x) Meyer bar coating; or xi) acombination of any two or more of i) to x). Typically, disposing thecurable composition on the substrate results in a wet deposit on thesubstrate, which is subsequently cured to give the coated substrate,which comprises a cured film formed from the curable composition on thesubstrate.

The substrate is not limited and may be any substrate. The cured filmmay be separable from the substrate or may be physically and/orchemically bonded to the substrate depending on its selection. Thesubstrate may have an integrated hot plate or an integrated orstand-alone furnace for curing the deposit. The substrate may optionallyhave a continuous or non-continuous shape, size, dimension, surfaceroughness, and other characteristics. Alternatively, the substrate mayhave a softening point temperature at the elevated temperature. However,the curable composition and method are not so limited.

Alternatively, the substrate may comprise a plastic, which maybe athermosetting and/or thermoplastic. However, the substrate mayalternatively be glass, metal, paper, wood, cardboard, paperboard, asilicone, or polymeric materials, or a combination thereof.

Specific examples of suitable substrates include paper substrates suchas Kraft paper, polyethylene coated Kraft paper (PEK coated paper), andregular papers; polymeric substrates such polyamides (PA); polyesterssuch as polyethylene terephthalates (PET), polybutylene terephthalates(PET), polytrimethylene terephthalates (PTT), polyethylene naphthalates(PEN), and liquid crystalline polyesters; polyolefins such aspolyethylenes (PE), polypropylenes (PP), and polybutylenes; styrenicresins; polyoxymethylenes (POM); polycarbonates (PC);polymethylenemethacrylates (PMMA); polyvinyl chlorides (PVC);polyphenylene sulfides (PPS); polyphenylene ethers (PPE); polyimides(PI); polyamideimides (PAI); polyetherimides (PEI); polysulfones (PSU);polyethersulfones; polyketones (PK); polyetherketones; polyvinylalcohols (PVA); polyetheretherketones (PEEK); polyetherketoneketones(PEKK); polyarylates (PAR); polyethernitriles (PEN); phenolic resins;phenoxy resins; celluloses such as triacetylcellulose,diacetylcellulose, and cellophane; fluorinated resins, such aspolytetrafluoroethylenes; thermoplastic elastomers, such as polystyrenetypes, polyolefin types, polyurethane types, polyester types, polyamidetypes, polybutadiene types, polyisoprene types, and fluoro types; andcopolymers, and combinations thereof.

The curable composition, or wet deposit, is typically cured at theelevated temperature for a period of time. The period of time istypically sufficient to effect curing, i.e., cross-linking, of thecurable composition. The period of time may be greater than 0 to 8hours, alternatively greater than 0 to 2 hours, alternatively greaterthan 0 to 1 hour, alternatively greater than 0 to 30 minutes,alternatively greater than 0 to 15 minutes, alternatively greater than 0to 10 minutes, alternatively greater than 0 to 5 minutes, alternativelygreater than 0 to 2 minutes. The period of time depends on variousfactors including on the elevated temperature is utilized, thetemperature selected, desired film thickness, and the presence ofabsence of any water or carrier vehicle in the curable composition.

Curing the curable composition typically has a dwell time of 0.1 secondand 50 seconds; alternatively 1 second to 10 seconds; and alternatively0.5 second to 30 seconds. Dwell time selected may depend on thesubstrate selection, temperature selected, and line speed. Dwell time,as used herein, refers to the time during which the curable composition,or wet deposit, is subjected to the elevated temperature. Dwell time isdistinguished from cure time, as there may be ongoing curing even afterthe curable composition, wet deposit, or partially cured reactionintermediary thereof is no longer subjected to the elevated temperature,which typically initiates curing. Alternatively, the coated article maybe prepared on a conveyor belt in an oven, and the dwell time may becalculated by dividing a length of the oven (e.g. in meters) by a linespeed of the conveyor belt (e.g. in meters/sec).

The period of time may be broken down into cure iterations, e.g. afirst-cure and a post-cure, with the first-cure being, for example, onehour and the post cure being, for example, three hours. The elevatedtemperature may be independently selected from any temperature aboveroom temperature in such iterations, and may be the same in eachiteration.

Depending on a thickness and other dimensions of the film and coatedsubstrate, the coated substrate can be formed via an iterative process.For example, a first deposit may be formed and subjected to a firstelevated temperature for a first period of time to give a partiallycured deposit. Then, a second deposit may be disposed on the partiallycured deposit and subjected to a second elevated temperature for asecond period of time to give a second partially cured deposit. Thepartially cured deposit will also further cure during exposure to thesecond elevated temperature for the second period of time. A thirddeposit may be disposed on the second partially cured deposit andsubjected to a third elevated temperature for a third period of time togive a third partially cured deposit. The second partially cured depositwill also further cure during exposure to the second elevatedtemperature for the second period of time. This process may be repeated,for example, from 1 to 50 times, to build the coated article as desired.A composite is of partially cured layers may be subjected to a finalpost-cure, e.g. at the elevated temperature and period of time above.Each elevated temperature and period of time may be independentlyselected and may be the same as or different from one another. When thearticle is formed via the iterative process, each deposit may also beindependently selected and may differ in terms of starting materialsselected in the curable composition, their amounts, or both.Alternatively still, each iterative layer may be fully cured, ratherthan only being partially cured, in such an iterative process.

Alternatively, the deposit may comprise a wet film. Alternatively, theiterative process may be wet-on-wet, depending on a cure state of thepartially cured layer. Alternatively, the iterative process may bewet-on-dry.

The coated substrate, which comprises the film formed from the curablecomposition on the substrate, may have varying dimensions, includingrelative thicknesses of the film and the substrate. The film has athickness that may vary depending upon its end use application. The filmmay have a thickness of greater than 0 to 4,000 μm, alternativelygreater than 0 to 3,000 μm, alternatively greater than 0 to 2,000 μm,alternatively greater than 0 to 1,000 μm, alternatively greater than 0to 500 μm, alternatively greater than 0 to 250 μm. However, otherthicknesses are contemplated, e.g. 0.1 to 200 μm. For example, thethickness of the film may be 0.2 to 175 μm; alternatively 0.5 to 150 μm;alternatively 0.75 to 100 μm; alternatively 1 to 75 μm; alternatively 2to 60 μm; alternatively 3 to 50 μm; and alternatively 4 to 40 μm.Alternatively, when the substrate is plastic, the film may have athickness of greater than 0 to 200, alternatively greater than 0 to 150μm, and alternatively greater than 0 to 100 μm.

If desired, the film may be subjected to further processing dependingupon its end use application. For example, the film may be subjected tooxide deposition (e.g. SiO₂ deposition), resist deposition andpatterning, etching, chemical, corona, or plasma stripping,metallization, or metal deposition. Such further processing techniquesare generally known. Such deposition may be chemical vapor deposition(including low-pressure chemical vapor deposition, plasma-enhancedchemical vapor deposition, and plasma-assisted chemical vapordeposition), physical vapor deposition, or other vacuum depositiontechniques. Many such further processing techniques involve elevatedtemperatures, particularly vacuum deposition, for which the film is wellsuited in view of its excellent thermal stability. Depending on an enduse of the film, however, the film may be utilized with such furtherprocessing.

The coated substrate may be utilized in diverse end use applications.For example, the coated substrate may be utilized in coatingapplications, packaging applications, adhesive applications, fiberapplications, fabric or textile applications, construction applications,transportation applications, electronics applications, or electricalapplications. However, the curable composition may be utilized in enduse applications other than preparing the coated substrate, e.g. in thepreparation of articles, such as silicone rubbers.

Alternatively, the coated substrate may be utilized as a release liner,e.g. for a tape or adhesive, including any pressure-sensitive adhesives,including acrylic resin-type pressure-sensitive adhesives, rubber-typepressure-sensitive adhesives, and silicone-type pressure-sensitiveadhesives, as well as acrylic resin-type adhesives, syntheticrubber-type adhesives, silicone-type adhesives, epoxy resin-typeadhesives, and polyurethane-type adhesives. Each major surface of thesubstrate may have a film disposed thereon for double sided tapes oradhesives.

Alternatively, when the curable composition will be formulated as arelease coating composition, the release coating composition may beprepared by mixing the starting materials together, for example, toprepare a one part composition. However, it may be desirable to preparea release coating composition as a multiple part composition, in whichstarting materials having SiH functionality (e.g., starting material(i), and when present (viii)) and hydrosilylation reaction catalyst arestored in separate parts, until the parts are combined at the time ofuse (e.g., shortly before application to a substrate).

For example, a multiple part composition may comprise:

Part (A) a base part comprising (ii) the polyorganosiloxane having anaverage, per molecule, of at least 2 silicon bonded aliphaticallyunsaturated hydrocarbon groups and iii) the hydrosilylation reactioncatalyst, and when present, one or more of, the anchorage additive, andthe solvent, and

Part (B) a curing agent part comprising (ii) the polyorganosiloxanehaving an average, per molecule, of at least 2 silicon bondedaliphatically unsaturated hydrocarbon groups and (i) the polyfunctionalorganohydrogensiloxane, and when present (viii) the substantially linearor linear polyorganohydrogensiloxane, the anchorage additive, thesolvent. Starting material (iv), the inhibitor may be added to eitherPart (A), Part (B), or both. Part (A) and Part (B) may be combined in aweight ratio (A):(B) of 1:1 to 10:1, alternatively 1:1 to 5:1, andalternatively 1:1 to 2:1. Part (A) and Part (B) may be provided in a kitwith instructions, e.g., for how to combine the parts to prepare therelease coating composition, how to apply the release coatingcomposition to a substrate, and how to cure the release coatingcomposition.

Alternatively, when the anchorage additive is present, it can beincorporated in either of Part (A) or Part (B), or it can be added in aseparate (third) part.

Alternatively, the release coating composition may be prepared by amethod comprising:

1) mixing starting materials comprising (ii) the polyorganosiloxanehaving an average, per molecule, of at least 2 silicon bondedaliphatically unsaturated hydrocarbon groups, (i) the polyfunctionalorganohydrogensiloxane, (iii) the hydrosilylation reaction catalyst,(iv) the inhibitor, and optionally one or more of (v) the anchorageadditive, (vi) the anti-mist additive, (vii) the controlled releaseagent, (viii) the linear polyorganohydrogensiloxane, and (ix) thesolvent, thereby forming a release coating composition;2) applying the mixture on a substrate. Step 1) may be performed bymixing Part (A) and Part (B) of a multiple part composition, asdescribed above.

The release coating composition can for example be applied to thesubstrate by any convenient means such as spraying, doctor blade,dipping, screen printing or by a roll coater, e.g. an offset web coater,kiss coater or etched cylinder coater.

The release coating composition of the invention can be applied to anysubstrate, such as those described above. Alternatively, the releasecoating composition may be applied to polymer film substrates, forexample polyester, particularly polyethylene terephthalate (PET),polyethylene, polypropylene, or polystyrene films. The release coatingcomposition can alternatively be applied to a paper substrate, includingplastic coated paper, for example paper coated with polyethylene,glassine, super calender paper, or clay coated kraft. The releasecoating composition can alternatively be applied to a metal foilsubstrate, for example aluminum foil.

The method may further comprise: 3) treating the substrate beforecoating the release coating composition on the substrate. Treating thesubstrate may be performed by any convenient means such as a plasmatreatment or a corona discharge treatment. Alternatively, the substratemay be treated by applying a primer. In certain instances anchorage ofthe release coating may be improved if the substrate is treated beforecoating.

When the release coating composition includes a solvent, the method mayfurther comprise: 4) removing solvent, which may be performed by anyconventional means, such as heating at 50° C. to 100° C. for a timesufficient to remove all or a portion of the solvent. The method mayfurther comprise 5) curing the release coating composition to form arelease coating on a surface of the substrate. Curing may be performedby any conventional means such as heating at 100° C. to 200° C.

Under production coater conditions, cure can be effected in a residencetime of 1 second to 6 seconds, alternatively 1.5 seconds to 3 seconds,at an air temperature of 120° C. to 150° C. Heating for steps 4) and/or5) can be performed in an oven, e.g., an air circulation oven or tunnelfurnace or by passing the coated film around heated cylinders.

EXAMPLES

These examples are intended to illustrate the invention and should notbe interpreted as limiting the scope of the invention set forth in theclaims. The starting materials in Table 1 were used in the examplesherein.

TABLE 1 Starting Materials Name Chemical Description Supplier MH-1109cyclic polymethylhydrogensiloxane Dow Silicones mixture having DP = 4 to6, crude (not purified after production) MH-1109, cyclicpolymethylhydrogensiloxane Dow Silicones stripped mixture having DP = 4to 6, stripped (to remove impurities after production) PA fluid, Silanolterminated polydimethylsiloxane, Dow Silicones 4-2737 average DP = 10.8PB fluid, Silanol terminated polyphenylmeth- Dow Silicones 4-2828ylsiloxane, average DP = 6.6 PI fluid, Silanol terminated Dow Silicones4-2830 polytrifluoropropylmethylsilxoane, average DP = 3.6 DMS-S42Silanol terminated polydimeth- Gelest ylsiloxane having average DP = 744BCF Tris(pentafluorophenyl)borane Millipore Sigma Al2O3 ActivatedAlumina, neutral Millipore Sigma Heptane n-heptane Millipore Sigma MIBKmethyl isobutyl ketone Millipore Sigma Allyl allyl glycidyl etherMillipore Sigma Glycidyl Ether

Reference Example 1—ESI-MS Analysis

Each sample was prepared at ca. 1000 ppm by dilution into Fisher HPLCgrade MeCN. The MeCN diluted samples were analyzed byflow-injection-analysis positive-ion electrospray ionization MS (FIA ESIMS). The instrument mass calibration was verified to be accurate on thesame day the analyses were performed. The instrument and conditionsbelow were used.

ESI-MS Instrumental Conditions Instrument: Agilent 1200 UPLC System

Flow Rate: 0.40 mL/min

Injection Volume: 2.5 uL

Mobile Phase: 95% MeCN in water

Positive-Ion ESI MS Conditions Instrument: Agilent 6520Quadrupole/Time-of-Flight (Q-TOF) Tandem Mass Spectrometer

Ion Source: Dual electrospray ionization

Mode: Positive Ion—MS1 Drying Gas Temp: 300° C. Drying Gas Flow Rate: 5L/min Nebulizer Pressure: 60 psi Fragmentor Voltage: 150 V SkimmerVoltage: 75V Octapolel RF Voltage: 750 V Capillary Voltage: 4500VReference Masses: 121.0509, 922.0098 Acquisition Mode: MS1 Mass Range:119-3200 Da

Scan Rate: 1 spectrum/sec

Reference Example 2—GPC

The following experimental procedure was used where the sample containedmethyl groups. Samples were prepared as follows.

Sample Prep: 10 mg/mL in eluent; solvated one hour with occasionalshaking; samples filtered through 0.45 μm PTFE syringe filters prior toinjectionPump: Waters 515 at a nominal flow rate of 1.0 mL/minEluent: HPLC grade tolueneInjector: Waters 717, 100 μL injectionColumns: Two (300 mm×7.5 mm) Polymer Laboratories PLgel 5 μm Mixed-Ccolumns,preceded by a PLgel 5 μm guard column (50 mm×7.5 mm), 45° C.Detection: Waters 2410 differential refractive index detector, 45° C.Data system: Atlas 8.3, Cirrus 2.0Calibration: Relative to 14 narrow polystyrene standards covering therange of 580 g/mole to 2,300,000 g/mole, fit to a 3rd order polynomialcurve

The following experimental procedure was used where the sample containedphenyl groups or trifluoropropyl groups.

Sample Prep: 10 mg/mL in eluent; solvated one hour; solutions filteredthrough 0.45 μm PTFE syringe filter prior to injectionPump: Waters 2695 at a nominal flow rate of 1.0 mL/minEluent: Certified grade THFInjector: Waters 2695, 100 μL injectionColumns: Two (300 mm×7.5 mm) Polymer Laboratories PLgel 5 μm Mixed-Ccolumns,preceded by a PLgel 5 μm guard column (50 mm×7.5 mm), 35° C.Detection: Waters 2410 differential refractive index detector, 35° C.Data system: Atlas 8.3, Cirrus 2.0Calibration: Relative to 16 narrow polystyrene standards covering therange of 580 g/mole to2,300,000 g/mole, fit to a 3rd order polynomial curve.

Reference Example 3—²⁹Si NMR

Samples were prepared for analysis as follows: 3.5-4.5 g sample wasdissolved in 4-4.5 g CDCl₃. Total weight 8-9 g. The sample wastransferred into a Teflon tube (8″ long x 13.5 mm O.D.) with a Teflonplug. ²⁹Si NMR data was acquired on a Varian Inova NMR (mi-MR-04)spectrometer with a ¹H operational frequency of 400 MHz. Standardparameters (nt=256 & d1=13) were applied.

Reference Example 4—General Procedure for Preparing PolyfunctionalOrganohydrogensiloxanes

A source of SiH (MH-1109 or MH-1109, stripped) was charged into a 1liter flask equipped with a mechanical stirrer, a thermal couple, and awater cooled condenser with N₂ bubbler. 10 ppm-100 ppm of BCF (dissolvedin toluene at 3-5%) was initially added into the flask at temperaturefrom RT to 50° C. A silanol fluid (PA, PB, or PI fluid) was slowly addedinto the flask under vigorous stirring. The reaction was monitored viapot temperature rise and gas generation. When no gas generation wasobserved, more BCF (10-100 ppm) was added to the flask. This operationwas repeated until the end of the addition of the silanol fluid. The pottemperature was maintained between 30° C.-60° C. during the course ofthe reaction. After completed the addition of the silanol fluid, themixture was maintained at 30° C.-60° C. for another 1-3 hours. Then heatwas removed and neutral activated alumina (300-1000 times by weight ofBCF catalyst) was added to the flask. The alumina was filtered outthrough a 0.45 μm filter membrane after stirring for 1-3 hours.Volatiles were removed via a rotary evaporator (<1 mmHg) at 80° C.-100°C. for 60-90 minutes. The resulting product was collected and analyzed.

Table 2 shows the samples generated using the general procedure inReference Example 4. Mw was measured according to Reference Example 2,PD was measured according to Reference Example 2, and % SiH was measuredaccording to Reference Example 3.

TABLE 2 Sample SiH source Silanol fluid MH-1109/OH ratio H % (as SiH) MwPD 1 MH-1109, PB fluid, n = 6.6 10.0 — 1730 1.25 stripped 2 MH-1109, PBfluid, n = 6.6 3.4 — 4710 1.45 stripped 3 MH-1109, PB fluid, n = 6.6 2.60.44% 11300 2.64 stripped 4 MH-1109, PI fluid, n = 3.6 2.0 0.70% 19301.59 stripped 5 MH-1109, PA fluid, n = 10.8 3.0 0.52% 5140 1.86 stripped6 MH-1109 PA fluid, n = 10.8 1.8 0.40% 5920 1.84 7 MH-1109 PA fluid, n =10.8 1.0 0.32% 69200 10.9

Sample 1 was analyzed according to the techniques in Reference Examples1-3. Sample 1 was found to have formula:

where 3≤p≤5, subscript n was 2 to 10, and each R was methyl, phenyl, ortrifluoropropyl.GPC results of the samples tested are shown in Table 3. Sample 5 had abroader distribution, which would indicate more crosslinking withcyclics termination. The polymer peak became broader as the molar ratioof MH-1109 to OH (r) decreased when comparing sample 5 (r=3.0) to sample6 (r=1.8). Without wishing to be bound by theory, it is thought thatthis shows that decreased MH-1109/OH ratio would lead to morecrosslinking or additional polyfunctional organohydrogensiloxanespecies.

The following molecular weight averages are relative to polystyrenestandards and are for the ° onions of the chromatograms as indicated.

TABLE 3 GPC Results molecular weight averages relative to polystyrenestandards Peak RT area Sample (min) Mp Mn Mw Mz PD % 5 13.1-18.2 29402760 5140 14800 1.86  98% 5 18.2-19.0 685 636 652 666 1.03 2.1% 613.4-18.2 4070 3210 5920 14500 1.84  98% 6 18.2-19.0 672 615 633 6491.03 2.0%

Additional samples were evaluated by GPC. These samples contained phenylgroups. Sample 1, which had MH-1109/OH ratio (r)=10, had a fairly narrowdistribution, which without wishing to be bound by theory, was thoughtto correspond to the product primarily comprising cyclics terminatedpolyfunctional organohydrogensiloxanes (without cyclics in the backboneof the organohydrogensiloxane). Sample 1 had a small high molecularweight tailing, which was expected to correspond to species having morethan one linear, and more than two cyclic, siloxane moieties permolecule. The polymer distribution became broader as the molar ratio ofMH-1109 to OH decreased along the series of Sample 1 (r=10), Sample 2(r=3.35) and Sample 3 (r=2.64). Without wishing to be bound by theory,it is thought that this was due to additional reaction of more than oneSiH on one molecule of C) the cyclic polyorganohydrogensiloxane and wassimilar to what was seen for the methyl containing samples. Results areshown below in Table 4.

TABLE 4 The following molecular weight averages are relative topolystyrene standards and are for the portions of the chromatograms asindicated. Sample Peak RT area Name (min) Mp Mn Mw Mz PD % 1 14.3-18.91370 1390 1730 3390 1.25 100%  2 13.8-17.2 2450 3250 4710 12000 1.45 39%2 17.2-19.0 1390 1250 1390 1480 1.11 61% 3 11.8-17.1 2720 4260 1130067100 2.64 58% 3 17.1-18.9 1470 1360 1470 1550 1.08 42%Sample 5A: Functionalizing the Polyfunctional Organohydrogensiloxane ofSample 5 with Epoxy Groups

262.5 g of the polyfunctional organohydrogensiloxane prepared asdescribed above by reference example 4 and shown in Table 2 as sample 5and 33.3 g of allyl glycidyl ether were mixed in a 4 neck flask equippedwith mechanical stirrer, thermal couple, water-cooled condenser adaptedto a N₂ bubbler. The pot temperature was raised to 50° C. 1454 of 0.012%Pt/toluene solution was added into the flask. The pot temperature raisedto 80° C. gradually in 10 minutes and then dropped to 65° C. in 5minutes. A heating block was used to maintain the pot temperature at 63°to 65° C. for one hour. Then volatiles were removed via rotaryevaporator at 80° C. and <1 mmHg for 50 minutes. 1.1 g of diallylmaleate was added to the flask after the contents were cooled to RT. Theresulting polyfunctional polyorganosiloxane had H (as SiH) content 0.32%and an average number of 2glycidyloxypropyl groups per molecule.

Comparative Example 5: Reaction of MH-1109 with PA Fluid Using PtCatalyst (Instead of BCF Catalyst)

113.6 g MH-1109 was charged into a 1 liter flask equipped with amechanical stirrer, a thermal couple, and a water cooled condenser withN₂ bubbler. 0.8 mL of 2.1% Pt/xylene solution was added and then 154.5 gof PA fluid was added slowly into the flask through an additionalfunnel. Pot temperature was controlled below 40° C. The PA fluid wascompletely added into the flask after 30 minutes. Viscosity increase wasobserved. A small sample was pulled out into an aluminum pan. Thematerial gelled after sitting in the hood for 1 hour 55 minutes.

Sample 5 from Table 2 was put into an aluminum pan. No visible change ofthe viscosity was observed after 5 weeks sitting in the hood underambient conditions. Sample 5 and Comparative Example 5 show that thepolyfunctional organohydrogensiloxane made using the process of thisinvention had better stability with time than a comparativeorganohydrogensiloxane made using the same hydroxyl terminatedpolydiorganosiloxane and cyclic polyorganohydrogensiloxane but withdifferent catalyst and method conditions.

Comparative Example 5A: Functionalizing the PolyfunctionalOrganohydrogensiloxane of Comparative Example 5 with Epoxy Groups

Comparative example 5 was repeated, except 30 g of allyl glycidyl etherwas added. The pot temperature gradually increased to 51° C. within 19minutes as a results from the exotherm from the hydrosilylationreaction. The pot temperature dropped to 23° C. after one hour. 1.19 gof diallyl maleate was added into the flask and mixed overnight.Volatiles was then removed via rotary evaporator at 40° C. and <1 mmHgfor 1 hour. The resulting clustered functional organopolysiloxane(having both glycidoxypropyl and SiH functionalities) had H (as SiH)content of 0.36%, and an average of 2 glycidoxypropyl groups permolecule.

The polyfunctional organohydrogensiloxanes prepared as described abovewere formulated into release coating compositions. The release coatingcompositions were coated on substrates, and cured to form releasecoatings. The starting materials used to prepare the release coatingcompositions are shown below in Table 5. The resulting release coatingcompositions and release coatings were evaluated as follows.

TABLE 5 Type Chemical description Source Branched A branchedpolydimethylsiloxane of formula Si{[OSi(CH₃)₂]v— Dow SiliconesCorporation Vinyl OSi(CH₃)₂CH═CH₂}₄ where subscript v is sufficient toprovide the Polymer polydimethylsiloxane with a vinyl content of 0.9%and Mn = 12,300 Da. Catalyst Karstedt's catalyst. Dow SiliconesCorporation Comparative Crosslinkers

Conventional Crosslinker 1: This crosslinker may be prepared viaplatinum catalyzed hydrosilylation reaction as described in U.S. Patent7,432,338. A trimethyl-siloxy terminatedpoly(dimethyl/methylhydrogen(siloxane Conventional Crosslinker copolymerhaving an SiH content of 1.01% and Mn = 1365. 2 is available from DowSilicones Corporation. This crosslinker may also be prepared viaplatinum catalyzed as hydrosilylation reaction described in U.S. Patent7,432,338.

Conventional Crosslinker 3: This crosslinker can be made via platinumcatalyzed hydrosilylation of a vinyl terminated polydimethylsiloxane,cyclic poly(methylhydrogen) siloxane, a platinum group metal catalyst,and an epoxy functional compound according to US Patent 9,593,209.Comparative Crosslinker

Conventional crosslinker 4: This crosslinker can be made via platinumcatalyzed addition reaction of a silanol terminatedpolydimethylsiloxane, cyclic poly(methylhydrogen) siloxane, and platinumgroup metal catalyst. This crosslinker was prepared in comparativeexample: 5A. New crosslinkers (prepared based unstripped MH-1109 INT)

Sample 6, Prepared according to Reference Example 4

Sample 7, Prepared according to Reference Example 4

Crosslinker Sample 5, Prepared according to Reference Example 4

Clustered functional organosiloxane Sample 5A. Inhibitor1-Ethynyl-1-cyclohexanol ETCH available from Millipore Sigma

Reference Example 6—Release Coating Composition

Inhibited Branched Vinyl Polymer and a crosslinker were mixed well atRT, and 120 grams of the resulting mixture was transferred into a 250 mLglass jar with cap. The capped glass jar was heated in a 40° C. waterbath for 50-60 mins. Catalyst was then introduced into the mixture whichwas then mixed further. Amounts of each starting material in releasecoating compositions prepared according to this Reference Example 6 areshown below in Table 6.

The release coating compositions in Table 6 were coated on Glassin Papercommercially available from UPM at a target coat weight of 1.3 g/m² a 3roll off set gravure coater. The resulting samples were cured at one ofthe following conditions: 400° F. for 1.2 seconds or 2.4 seconds or 166°C. for 1.5 seconds, 2 seconds or 3 seconds.

TABLE 6 Release Coating Compositions (F1, F2, and F3). Amounts of eachstarting material are in grams. F1 F2 F3 Starting Material (Comparative)(Working) (Working) Inhibited Branched Vinyl 122.23 79.32 76.55 PolymerKarstedt's Catalyst 0.81 0.54 0.54 Conventional Crosslinker 1 16.83 0 0Sample 6 (polyfunctional 0 13.38 0 organohydrogensiloxane) Newcrosslinker Sample 7 (polyfunctional 0 0 16.15 organohydrogensiloxane)New crosslinker

Reference Example 7—Release Coating Compositions

Release coating composition samples F4 to F10 were prepared as follows:Branched Vinyl Polymer and Crosslinker were mixed mechanically at RT.Inhibitor was added and mixed well again. Catalyst was then added andmixed at RT. Amounts of each starting material in Release coatingcompositions F4-F10 are shown below in Table 7, in grams.

The release coating compositions in Table 7 were coated on Glassin Papercommercially available from UPM at a target coat weight of 1.3 g/m². Theresulting samples were cured at one of the following conditions: 166° C.for 1.5 or 3 seconds and 182° C. for 1.5 seconds or 3 seconds or 204°for 1.2 seconds.

TABLE 7 Release Coating Compositions F4 F5 F6 F7 F8 F9 F10 StartingMaterial (C) (W) (C) (W) (C) (W) (C) Branched Vinyl Polymer 443.56442.59 414.04 419.91 462.06 462.11 427.21 Inhibitor (ETCH) 1.09 1.091.09 1.09 1.09 1.09 1.09 Karstedt's Catalyst 2.89 2.89 2.89 2.89 2.892.89 2.89 Conventional 52.46 0 0 0 0 0 0 Crosslinker 1 (Comparative)Crosslinker Sample 5 0 53.44 0 0 0 0 0 Conventional 0 0 81.99 0 10.19 00 Crosslinker 3 (Comparative) Clustered Functional 0 0 0 76.12 0 10.51 0Organosiloxane Sample 5A (Working) Conventional 0 0 0 0 0 0 68.82crosslinker 4 Conventional 0 0 0 0 23.78 23.40 Crosslinker 2

Reference Example 8—Bulk Bath Life Test

The bulk bathlife of the release coating formulations were tested byusing the following procedures: Inhibited Branched Vinyl Polymer, acrosslinker, and Inhibitor were mixed well at RT, and 120 grams of theresulting mixture was transferred into a 250 mL glass jar with cap. Thecapped glass jar was heated in a 40° C. water bath for 50-60 mins.Catalyst was then introduced into the mixture, which was then mixedfurther. The hours when the viscosity doubled at 40° C. was defined asthe bulk bathlife. Samples of release coating compositions were preparedwith the starting materials described above in Reference Examples 6 and7. The viscosity was measured by Brookfield DV-II viscometer with the #3spindle.

Reference Example 9—Thin Film Bath Life Test

Samples of release coating compositions were prepared as described abovein Reference Example 7. Thin Film Bath Life was measured as follows. A 2mil Bird Bar was used to coat the sample on a 1 MIL PET film. Theresulting film was checked every 5 minutes. The time when the filmbecame smudged or partially cured was defined as the thin film bath lifeof the release coating.

Results of bath life studies from Reference Examples 8 and 9 are shownbelow in Table 8.

TABLE 8 Thin film bath life and bulk bath life study results. F4 F5 F6F7 F10 (C) (W) (C) (W) (C) Thin film bath >260 >260 200 >260 >260 life(mins) Bulk bath life >4 >4 >4 >4 4 (hrs)

Thin film bath life and bulk bathlife are important for release coatingcompositions. Generally, customers desire longer thin film and bulk bathlife to ensure the release coating composition does not cure beforeprocess to coat it on a substrate is completed. The data in Table 9 showthat the polyfunctional organohydrogensiloxanes produced by the newmethod herein will produce release coating compositions having similarthin film bath life and similar bulk bath life when compared tocommercial crosslinkers. Using the polyfunctionalorganohydrogensiloxanes produced by the new method herein will besuitable for use in customers' existing equipment and processes.Furthermore, sample F7 demonstrated longer thin film bathlife than F6(control containing a commercial crosslinker) and longer bulk bathlifethan F10 (containing a comparative crosslinker prepared via Pt catalystSiOH/SiH condensation), confirming the Clustered functionalorganosiloxane sample 5A prepared via BCF route has advantages over theconventional crosslinker 3 and conventional crosslinker 4 prepared viaPt catalyzed hydrosilylation reaction from bathlife perspective.

Reference Example 9—Testing Procedure for Extractables

Extractable % corresponds to how well the release coating is cured. Tomeasure the cure performance of the release coating compositions, anextractable test was undertaken immediately after cure. The extractabletest was utilized to identify the amount of non-crosslinked siliconethat was extractable from a cured release coating sample in the presenceof a solvent. The test method used for the following example was asfollows:

-   1. Immediately upon completion of the coating process (described    above) three sample discs were cut from a coated substrate using a    1.375 inch (3.49 cm) die cutter.-   2. The silicone coat weight on each sample was determined using an    Oxford Instruments Lab-X 3500 Benchtop XRF analyzer-   3. Each disc was then placed in an individual 100-mL bottle    containing 40 mL of methyl isobutyl ketone solvent. Tweezers were    used for handling sample discs at all times to ensure that the    silicone surface of the sample was uncontaminated or damaged. The    solvent bottles were then covered with lids and allowed to rest on    the laboratory bench for 30 minutes. After this period the discs    were removed from the solvent and placed on clean tissue paper, with    the silicone coated side up.-   4. The solvent was allowed to evaporate from the sample discs    without wiping or blotting the samples.-   5. The final coat weight of each sample disc was then determined.-   6. The percent of extractable was calculated using the following    formula:

${Extractable}\mspace{14mu}\%{= {\frac{\left( {W_{i} - W_{f}} \right)}{W_{i}} \times 100\%}}$

W_(i)=initial coat weight (before solvent introduction)

W_(f)=final coat weight (after solvent evaporation)

Release coatings compositions were prepared, coated on Glassin Paper andcured as described above in Reference Example 7 were evaluated forextractables by the method of Reference Example 9. Results are in Table9, below.

TABLE 9 Extractable % of release coatings prepared Curing Dwelltemperature time F4 F5 F6 F7 F8 F9 F10 (° C.) (s) (C) (W) (C) (W) (C)(W) (C) 166 1.5 7.38 ± 0.83 3.98 ± 1.33 2.23 ± 2.04 4.13 ± 0.03 4.14 ±1.35 3.25 ± 0.97 9.88 ± 1.44 3 1.39 ± 0.02 3.10 ± 2.04 2.20 ± 2.01 2.31± 0.81 1.83 ± 0.79 1.82 ± 0.73 6.40 ± 0.86 182 1.5 7.11 ± 2.04 4.02 ±0.03 2.29 ± 0.78 4.67 ± 0.77 1.38 ± 0.03 3.19 ± 0.75 NA 3 2.75 ± 1.363.15 ± 0.78 3.27 ± 1.60 2.32 ± 0.79 2.72 ± 1.33 2.24 ± 0.77 NA 204 1.24.57 ± 0.79 3.53 ± 3.31 2.21 ± 0.76 5.14 ± 0.79 2.70 ± 0.00 1.85 ± 1.60NA

These examples show that under the conditions tested, sample formulationF5, including a polyfunctional organohydrogensiloxane (crosslinkersample 5) made by the method described herein had lower extractables(faster cure) when cured at shorter dwell time and the same temperaturethan formulation F4, which was a comparable composition made with acommercially available crosslinker produced via Pt catalyzedhydrosilylation (Conventional crosslinker 1). Without wishing to bebound by theory, it is thought that shorter dwell time means fast coaterline speed and higher production efficiency.

Sample F7 contained Clustered functional organosiloxane sample 5A madeby the method described herein, and Sample F7 had comparable extractable% compared with sample F6 (containing a comparative crosslinker made byPt catalyzed hydrosilylation, i.e., Conventional crosslinker 3) at threetemperatures and relatively longer dwell time—3 second. With relativeshort dwell time, sample F7 demonstrated comparable extractable % to F6when error is considered. Sample F7 showed an advantage over Sample F10(containing a comparative crosslinker, i.e., conventional crosslinker 4,which was prepared via Pt catalyzed SiH/SiOH condensation route) fromextractable % perspective. Generally speaking, sample F7 containing aclustered functional organosiloxane prepared via the method of thisinvention is comparable compared with sample F6 containing a crosslinkerprepared via Pt catalyzed hydrosilylation reaction between vinylendcapped difunctional polydimethylsiloxane, MH-1109, and allyl glycidylether. However, sample F7 performed much better than sample F10containing a crosslinker made Pt catalyzed reaction between silanolendcapped difunctional polydimethylsiloxane, MH-1109, and allyl glycidylether from extractable % perspective. In addition, the clusteredfunctional organosiloxane used in sample formulation F7 was much cheaperthan the crosslinkers used in samples F6 and F10. When the sameclustered functional organosiloxane used in formulation F7 was insteadused as a co-crosslinker (in sample F9) with Conventional Crosslinker 2,similarly, it demonstrated similar extractable % compared with the samecrosslinker in F6 blended with Conventional Crosslinker 2 (in sample F8)across all the temperatures and dwell times tested.

Reference Example 10—ROR % Evaluations

ROR % informs how well a release coating is bonded to a substrate. Thepercent rub off resistance (ROR %) test (sometimes referred to asanchorage index) measures the amount of cured silicone left after thecoated substrate has been subjected to surface abrasion. It indicateshow strong the cured coating film is anchored to the substrate; thehigher the ROR % value the better. The ROR % is measured as soon as thecoated substrate exits the curing oven. From each coated substrate, 2sample discs were prepared and the silicone present in each sample discof the coated substrate is then determined via an Oxford InstrumentsLab-X 3500 Benchtop XRF analyzer. Each sample disc of the coatedsubstrate was then subjected to an abrasion test under a load of 1.9 kgand in contact with a felt using automated abrading equipment, in amanner similar to a ‘Taber-type method’. The ROR % is calculated asfollows:

ROR%=(W _(f) /W _(i))×100

W_(i)=initial coat weight (before abrasion)

W_(f)=final coat weight (after abrasion)

Release Coatings Compositions were prepared, coated on Glassin Paper andcured as described above in Reference Example 7. The resulting releaseliner samples were evaluated for ROR by the method of Reference Example10. Results are in Table 10.

TABLE 10 Immediate ROR % of Release Coatings prepared according toReference Example 7 Curing Dwell temperature time F4 F5 F6 F7 F8 F9 F10(° C.) (s) (C) (W) (C) (W) (C) (W) (C) 166 1.5 86.78 ± 4.55 20.78 ± 1.8448.95 ± 9.98 54.49 ± 1.51 24.23 ± 5.57 82.04 ± 6.03 0.00 ± 0  3 81.82 ±0.18 99.32 ± 0.96 97.96 ± 0.94 86.62 ± 2.99 99.31 ± 0.98 96.60 ± 0.9362.76 ± 0.36 182 1.5 88.36 ± 0.97 29.98 ± 9.91 92.93 ± 1.79 89.90 ± 6.2156.67 ± 5.51 88.86 ± 3.63 NA 3 95.77 ± 0.00 99.32 ± 0.96 97.10 ± 0.0090.97 ± 1.27 96.54 ± 0.91 98.65 ± 0.00 NA 204 1.2 88.97 ± 1.84 33.38 ±8.98 94.67 ± 0.00 85.00 ± 1.01  49.71 ± 12.19 80.45 ± 5.74 NA

Without wishing to be bound by theory, it is thought that customersprefer short dwell times for release coating applications because higherline speeds, and higher production efficiencies) are possible withshorter dwell times. Rub off resistance indicates how well the releasecoating is bonded to a substrate, therefore, it is desirable to havehigh rub off resistance at short dwell time (high initial rub offresistance).

As shown in Table 10, across all temperatures and dwell times tested,sample formulation F5 containing a polyfunctional organohydrogensiloxane(Crosslinker sample 5), which was made by the method described herein,showed the advantage of having higher rub off resistance percentage (ROR%) than sample formulation F4 containing a comparative crosslinker(Conventional crosslinker 1), which was produced via Pt catalyzedhydrosilylation.

Sample formulation F7, containing a clustered functional organosiloxane(Clustered functional organosiloxane sample 5A) made by the methoddescribed herein, had comparable ROR % compared with sample formulationF6 (containing a comparative crosslinker, Conventional crosslinker 3,which was made via Pt catalyzed hydrosilylation) across all temperaturesand dwell times tested. Sample F7 showed much higher ROR % than sampleF10 (containing a comparative crosslinker, Conventional crosslinker 4,which was prepared via Pt catalyzed SiH/SiOH condensation route) fromROR % perspective. Generally speaking, the clustered functionalorganosiloxane prepared by the method described herein and used insample F7 was comparable compared with the comparative crosslinker insample F6 and was much better than the crosslinker in sample F10 fromROR % perspective.

When the same clustered functional organosiloxane used in sampleformulation F7 was used as a co-crosslinker (in sample formulation F9)with Conventional Crosslinker 2, similarly, it demonstrated similar ROR% compared with the same crosslinker in sample formulation F6 blendedwith Conventional Crosslinker 2 (in sample formulation F8) across alltemperatures and dwell times tested.

Reference Example 11 Aged ROR % Evaluations

An accelerated aged anchorage test was performed as follows. Releaseliner samples were aged at 85% RH and 65° C. for 1 week. Additionalrelease liner samples were aged at RT under constant humidity (RH=51%)and pressure for 1 month and 3 month. Then, ROR was tested as describedabove in Reference Example 10.

Release Coating Compositions were prepared, coated on Glassin Paper andcured as described above in Reference Example 7. The resulting releaseliner samples were aged and tested according to Reference Example 13.The results are in Tables 12 and 13 below.

TABLE 11 1 week aged ROR % under the conditions of 85 RH % and 65 C.Curing Dwell temperature time F4 F5 F6 F7 F8 F9 F10 (° C.) (s) (C) (W)(C) (W) (C) (W) (C) 166 1.5 40.90 ± 0.13 46.36 ± 0.66 99.95 ± 0.08  100± 0.00 98.94 ± 0.91  100 ± 0.03 60.72 ± 2.43 3 73.07 ± 1.22 95.46 ± 2.5898.65 ± 0.11 99.10 ± 0.22 97.10 ± 0.68 97.93 ± 0.62 91.63 ± 3.14 182 1.543.19 ± 1.50 56.37 ± 3.62 99.31 ± 0.69  100 ± 0.00 99.43 ± 0.09  100 ±0.00 NA 3 93.84 ± 0.64 97.76 ± 2.88 99.10 ± 0.05 96.88 ± 1.29 98.93 ±0.63 98.48 ± 0.83 NA 204 1.2 42.95 ± 0.18 55.36 ± 4.95 99.09 ± 1.1499.17 ± 0.60 99.98 ± 1.43 99.24 ± 0.09 NA

As shown in Table 11, sample formulation F5 including a polyfunctionalorganohydrogensiloxane (Crosslinker sample 5) made by the methoddescribed herein haver much higher 1 week 85% RH and 65° C. acceleratedrub off resistance percentage (ROR %) than sample formulation F4including a comparative organohydrogensiloxane (Conventional crosslinker1), which was produced via Pt catalyzed hydrosilylation, across alltemperature and dwell times tested.

Sample Formulation F7 containing a clustered functional organosiloxane(Clustered functional organosiloxane sample 5A) made by the methoddescribed herein, had comparable 1 week 85% RH and 65° C. acceleratedrub off resistance percentage (ROR %) compared with sample formulationF6 (containing a comparative crosslinker made via Pt catalyzedhydrosilylation) across all temperatures and dwell times tested. Sampleformulation F7 showed much higher 1 week 85% RH and 65° C. acceleratedROR % than sample formulation F10 (containing a comparative crosslinkerprepared via Pt catalyzed SiH/SiOH condensation route) from an ROR %perspective. Generally speaking, the crosslinker used in sampleformulation F7 prepared via BCF route was comparable compared with thecrosslinker in sample formulation F6 prepared via Pt catalyzedhydrosilylation reaction between vinyl endcapped difunctionalPDMS/MH-1109/allyl glycidyl ether, but much better than the crosslinkerin sample formulation F10 (Conventional crosslinker 4), which was madeby Pt catalyzed reaction between silanol endcapped difunctional PDMS,MH-1109, and allyl glycidyl ether from 1 week 85% RH and 65° C.accelerated ROR % perspective.

When the same clustered functional organosiloxane in F7 was used as aco-crosslinker (in sample F9) with Conventional Crosslinker 2,similarly, it demonstrated similar ROR % compared with the samecrosslinker in F6 blended with Conventional crosslinker 2 (in sampleformulation F8) across all temperatures and dwell times tested. Theseexamples further show that sample formulation F5 had superior anchorageperformance over sample formulation F4 in the accelerated anchorage agedanchorage study; and sample formulation F7 had improved anchorageperformance compared to sample formulation F10.

TABLE 12 1 month RT aged ROR %. Curing Dwell temperature time F4 F5 F6F7 F8 F9 F10 (° C.) (s) (C) (W) (C) (W) (C) (W) (C) 166 1.5 13.92 ± 3.5392.47 ± 0.97 99.32 ± 0.96 99.28 ± 1.02 97.18 ± 0.00 97.92 ± 0.98  2.12 ±1.04 3 88.89 ± 1.96 96.72 ± 0.87 98.57 ± 0.03 97.92 ± 0.98 98.63 ± 0.0397.94 ± 0.96 82.28 ± 2.83 182 1.5 19.44 ± 5.89 89.80 ± 0.86  100 ± 0.0099.28 ± 1.02 97.18 ± 0.00 97.93 ± 0.94 NA 3 95.77 ± 0.08 98.59 ± 1.9998.55 ± 2.05 98.59 ± 0.03 97.14 ± 0.06 98.57 ± 0.00 NA 204 1.2 13.10 ±0.85 91.83 ± 2.00 98.01 ± 0.91 98.58 ± 0.01 98.57 ± 0.03 99.30 ± 1.00 NA

As shown in Table 12, similarly, sample formulation F5 containing apolyfunctional organohydrogensiloxane (Crosslinker sample 5) made by themethod described herein had improved 1 month RT aged ROR % than sampleformulation F4 containing a comparative crosslinker (Conventionalcrosslinker 1, which was produced via Pt catalyzed hydrosilylation)across all temperatures and dwell times tested, especially with shorterdwell time. The polyfunctional organohydrogensiloxane made by the methodherein demonstrated a big improvement.

Sample formulation F7 containing a clustered functional organosiloxanemade by the method described herein, had comparable 1 month RT aged ROR% compared with sample formulation F6 (containing a comparativecrosslinker produced via Pt catalyzed hydrosilylation) across alltemperatures and dwell times tested. Sample formulation F7 showed muchhigher 1 month RT aged ROR % than Sample formulation F10 (whichcontained a comparative crosslinker prepared via a Pt catalyzed SiH/SiOHcondensation route) from ROR % perspective. Generally speaking, theclustered functional organosiloxane produced by the method describedherein and used in sample formulation F7 had comparable ROR % ascompared to sample formulation F6 containing a comparative crosslinker(which was prepared via Pt catalyzed hydrosilylation reaction betweenvinyl endcapped difunctional PDMS, MH-1109, and allyl glycidyl ether),but much better than sample formulation F10 containing a comparativecrosslinker (which was made via Pt catalyzed reaction between silanolendcapped difunctional PDMS, MH-1109, and allyl glycidyl ether) from 1month RT aged ROR % perspective.

When the clustered functional organosiloxane in sample formulation F7was used as a co-crosslinker (in sample F9) with ConventionalCrosslinker 2, similarly, it demonstrated similar 1 month RT aged ROR %compared with the same crosslinker in sample formulation F6 blended withComparative Crosslinker 2 (in sample F8) across all temperatures anddwell times tested.

These examples further show that sample formulation F5 had superioranchorage performance over sample formulation F4 in the acceleratedanchorage aged anchorage study; and sample formulation F7 had improvedanchorage performance compared to sample formulation F10.

TABLE 12 1 month RT aged release force profile - 166° C./3 s sample withTesa 7475 tape. Aging Peeling time speed Release force (cN/25 mm)(months) (m/min) F4 (C) F5 (W) F6 (C) F7 (W) F8 (C) F9 

1 month 0.3 11.33 ± 0.12  25.27 ± 0.40  34.27 ± 2.36  65.36 ± 3.34 21.50± 1.22 25.07 

10 41.07 ± 0.57  73.93 ± 5.55  98.75 ± 7.43 142.19 ± 7.16 52.22 ± 0.9664.55 

100 78.18 ± 6.29 109.32 ± 0.71 142.57 ± 1.05  162.57 ± 14.27 114.86 ±7.78  102 

300 65.02 ± 3.23 109.38 ± 1.36 136.25 ± 9.91 127.48 ± 5.48 71.30 ± 1.6678.23 

3 months 0.3 11.33 ± 0.12  25.52 ± 0.87  44.56 ± 2.60  86.12 ± 2.6821.95 ± 0.59 24.14 

10 35.56 ± 0.38 101.74 ± 6.59 111.44. ± 6.28  193.85 ± 2.03 97.25 ± 3.4796.87 

100 68.48 ± 4.50 120.80 ± 1.01 214.03 ± 0.46 231.95 ± 5.94 116.38 ±2.00  125.86 

300 57.03 ± 2.07 88.36 ± 2.0 161.62 ± 2.11 197.00 ± 7.97 85.43 ± 2.8394.00 

indicates data missing or illegible when filed

These examples show that under the conditions tested: sample formulationF5 and sample formulation F7 each containing a product (Crosslinkersample 5 in F5 and Clustered functional organosiloxane sample 5A in F7)made by the method described herein have higher release force than theiranalogues sample formulation F4 (containing Conventional crosslinker 1)and sample formulation F6 (containing Conventional crosslinker 3),respectively, each containing a comparative crosslinker produced via Ptcatalyzed hydrosilylation. The new polyfunctionalorganohydrogensiloxanes made by the method described herein arepotential successful crosslinkers used for relatively high release forcerequirement applications.

INDUSTRIAL APPLICABILITY

A new method to prepare polyfunctional organohydrogensiloxanes havingcyclic SiH functional end groups linked via oxygen atoms to linearpolydiorganosiloxanes was developed. The method provides the benefit ofallowing control of the polyfunctional organohydrogensiloxanearchitecture to maximize the amount of polyfunctionalorganohydrogensiloxane of formula a-2) described above (and reduce orminimize potential for subscript o′>0 in unit formula a-1), describedabove) when desired. For example, by controlling ratio of cyclicpolyorganohydrogensiloxane and hydroxyl terminated polydiorganosiloxanecan result in a polyfunctional organohydrogensiloxane with two cyclicmoieties linked via oxygen atom at the ends of a linearpolydiorganosiloxane (as shown in formula a-2)). The examples above showthat under the conditions tested, as the ratio of cyclicpolyorganohydrogensiloxane (e.g., MH-1109 in the examples above) andhydroxyl terminated polydiorganosiloxane (e.g., PA fluid, PB fluid, orPI fluid) decreases, there are more chances to form species whereinsubscript o′>0 such as:

(where o′ is 1 or 2, respectively)As a result, Mw and polydispersity (PD) increase with decreasingMH-1109/OH ratio.

The inventors further surprisingly found that the polyfunctionalorganohydrogensiloxane prepared by the method described herein canprovide one or more benefits when used in a release coating composition,as compared to a commercially available organohydrogensiloxane preparedby a process described, e.g., in U.S. Pat. No. 7,432,338. Processesinvolving platinum catalyzed hydrosilylation of a cyclicpolymethylhydrogensiloxane and vinyl terminated polydimethylsiloxane(e.g., to produce crosslinkers such as Conventional Crosslinker 1 andConventional Crosslinker 3 used above in the comparative examples), andplatinum catalyzed addition reaction of a cyclicpolymethylhydrogensiloxane and hydroxyl terminated polydimethylsiloxane(e.g., to produce the crosslinker of Comparative Example 5A) were usedto produce comparative crosslinkers. When these comparative crosslinkersand the crosslinkers prepared by the method described herein wereformulated into release coating compositions, coated on substrates, andcured, the inventors found that one or more of the following benefitswere exhibited: the release coating compositions had better bulk bathlife, thin film bath life, and/or cure performance, and cured releasecoatings had lower extractables, higher anchorage, and/or higher releaseforce than the release coating compositions and release coatings madetherefrom containing the comparative crosslinkers.

Definitions and Usage of Terms

Abbreviations used in the specification have the definitions in Table 5,below.

TABLE 5 Abbreviations Abbreviation Definition cP centiPose d day DaDaltons DP degree of polymerization FTIR Fourier Transfer Infra-Red ggrams GC gas chromatography GPC gel permeation chromatography HPLC highperformance liquid chromatography Me methyl mg milligrams MHz megaHertzmL milliliters mm millimeters Mn number average molecular weight asmeasured by GPC as described in Reference Example 2 Mp Peak molecularweight as measured by GPC as described in Reference Example 2 mPa · smilli-Pascal seconds MS mass spectroscopy Mw weight average molecularweight Mz Z-average molecular weight NMR nuclear magnetic resonance O.D.outer diameter PD polydispersity Ph phenyl ppm parts per million PTFEpolytetrafluoroethylene RH relative humidity RT room temperature of 25°C. s seconds SiH content hydrogen, as silicon bonded hydrogen, asmeasured by 29 Si NMR as described in Reference Example 3 THFtetrahydrofuran μL microliter μm micrometer Vi vinyl

All amounts, ratios, and percentages are by weight unless otherwiseindicated. The amounts of all starting materials in a composition total100% by weight. The SUMMARY and ABSTRACT are hereby incorporated byreference. The articles ‘a’, ‘an’, and ‘the’ each refer to one or more,unless otherwise indicated by the context of specification. The singularincludes the plural unless otherwise indicated. The disclosure of rangesincludes the range itself and also anything subsumed therein, as well asendpoints. For example, disclosure of a range of 2.0 to 4.0 includes notonly the range of 2.0 to 4.0, but also 2.1, 2.3, 3.4, 3.5, and 4.0individually, as well as any other number subsumed in the range.Furthermore, disclosure of a range of, for example, 2.0 to 4.0 includesthe subsets of, for example, 2.1 to 3.5, 2.3 to 3.4, 2.6 to 3.7, and 3.8to 4.0, as well as any other subset subsumed in the range. Similarly,the disclosure of Markush groups includes the entire group and also anyindividual members and subgroups subsumed therein. For example,disclosure of the Markush group a hydrogen atom, an alkyl group, analkenyl group, or an aryl group, includes the member alkyl individually;the subgroup alkyl and aryl; and any other individual member andsubgroup subsumed therein.

“Alkyl” means a branched or unbranched, saturated monovalent hydrocarbongroup. Examples of alkyl groups include methyl, ethyl, propyl (includingn-propyl and/or iso-propyl), butyl (including iso-butyl, n-butyl,tert-butyl, and/or sec-butyl), pentyl (including, iso-pentyl, neopentyl,and/or tert-pentyl); and n-hexyl, n-heptyl, n-octyl, n-nonyl, andn-decyl, as well as branched saturated monovalent hydrocarbon groups of6 or more carbon atoms. Alkyl groups have at least one carbon atom.Alternatively, alkyl groups may have 1 to 18 carbon atoms, alternatively1 to 12 carbon atoms, alternatively 1 to 6 carbon atoms, alternatively 1to 4 carbon atoms, alternatively 1 to 2 carbon atoms, and alternatively1 carbon atom.

“Aralkyl” and “alkaryl” each refer to an alkyl group having a pendantand/or terminal aryl group or an aryl group having a pendant alkylgroup. Exemplary aralkyl groups include benzyl, tolyl, xylyl, dimethylphenyl, phenylmethyl, phenylethyl, phenyl propyl, and phenyl butyl.Aralkyl groups have at least 7 carbon atoms. Monocyclic aralkyl groupsmay have 7 to 12 carbon atoms, alternatively 7 to 9 carbon atoms, andalternatively 7 to 8 carbon atoms. Polycyclic aralkyl groups may have 7to 17 carbon atoms, alternatively 7 to 14 carbon atoms, andalternatively 9 to 10 carbon atoms.

“Alkenyl” means a branched, or unbranched monovalent hydrocarbon group,where the monovalent hydrocarbon group has a double bond. Alkenyl groupsinclude vinyl, allyl, and hexenyl. Alkenyl groups have at least 2 carbonatoms. Alternatively, alkenyl groups may have 2 to 12 carbon atoms,alternatively 2 to 10 carbon atoms, alternatively 2 to 6 carbon atoms,alternatively 2 to 4 carbon atoms, and alternatively 2 carbon atoms.

“Alkynyl” means a branched, or unbranched monovalent hydrocarbon group,where the monovalent hydrocarbon group has a triple bond. Alkynyl groupsinclude ethynyl and propynyl. Alkynyl groups have at least 2 carbonatoms. Alternatively, alkynyl groups may have 2 to 12 carbon atoms,alternatively 2 to 10 carbon atoms, alternatively 2 to 6 carbon atoms,alternatively 2 to 4 carbon atoms, and alternatively 2 carbon atoms.

“Aryl” means a hydrocarbon group derived from an arene by removal of ahydrogen atom from a ring carbon atom. Aryl is exemplified by, but notlimited to, phenyl and naphthyl. Aryl groups have at least 5 carbonatoms. Monocyclic aryl groups may have 5 to 9 carbon atoms,alternatively 6 to 7 carbon atoms, and alternatively 6 carbon atoms.Polycyclic aryl groups may have 10 to 17 carbon atoms, alternatively 10to 14 carbon atoms, and alternatively 12 to 14 carbon atoms.

“Carbocycle” and “carbocyclic” refer to a hydrocarbon ring. Carbocyclesmay be monocyclic or polycyclic, e.g., bicyclic or with more than tworings. Bicyclic carbocycles may be fused, bridged, or spiro polycyclicrings. Carbocycles have at least 3 carbon atoms. Monocyclic carbocyclesmay have 3 to 9 carbon atoms, alternatively 4 to 7 carbon atoms, andalternatively 5 to 6 carbon atoms. Polycyclic carbocycles may have 7 to17 carbon atoms, alternatively 7 to 14 carbon atoms, and alternatively 9to 10 carbon atoms. Carbocycles may be saturated (e.g., cyclopentane orcyclohexane), partially unsaturated (e.g., cyclopentene or cyclohexene),or fully unsaturated (e.g., cyclopentadiene or cycloheptatriene).

“Cycloalkyl” refers to a saturated hydrocarbon group including acarbocycle. Cycloalkyl groups are exemplified by cyclobutyl,cyclopentyl, cyclohexyl, and methylcyclohexyl. Cycloalkyl groups have atleast 3 carbon atoms. Monocyclic cycloalkyl groups may have 3 to 9carbon atoms, alternatively 4 to 7 carbon atoms, and alternatively 5 to6 carbon atoms. Polycyclic cycloalkyl groups may have 7 to 17 carbonatoms, alternatively 7 to 14 carbon atoms, and alternatively 9 to 10carbon atoms.

“Monovalent hydrocarbon group” means a univalent group made up ofhydrogen and carbon atoms. Monovalent hydrocarbon groups include alkyl,aralkyl, alkenyl, alkynyl, and cycloalkyl groups as defined above.

“Monovalent halogenated hydrocarbon group” means a monovalenthydrocarbon group where one or more hydrogen atoms bonded to a carbonatom have been formally replaced with a halogen atom. Halogenatedhydrocarbon groups include haloalkyl groups, halogenated carbocyclicgroups, and haloalkenyl groups. Halogenated alkyl groups (or haloalkylgroups) include the alkyl groups or cycloalkyl groups described abovewhere one or more of the hydrogen atoms is replaced with a halogen atom,such as F or Cl. Haloalkyl groups include fluorinated alkyl groups andfluorinated cycloalkyl groups such as trifluoromethyl (CF₃),fluoromethyl, trifluoroethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl,4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl,8,8,8,7,7-pentafluorooctyl, 2,2-difluorocyclopropyl,2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and3,4-difluoro-5-methylcycloheptyl; and chlorinated alkyl and chlorinatedcycloalkyl groups such as chloromethyl, 3-chloropropyl2,2-dichlorocyclopropyl, 2,3-dichlorocyclopentyl. Haloalkenyl groupsinclude chloroallyl. Halogenated aryl groups include chlorobenzyl andfluorobenzyl.

The term “comprising” and derivatives thereof, such as “comprise” and“comprises” are used herein in their broadest sense to mean andencompass the notions of “including,” “include,” “consist(ing)essentially of,” and “consist(ing) of. The use of “for example,” “e.g.,”“such as,” and “including” to list illustrative examples does not limitto only the listed examples. Thus, “for example” or “such as” means “forexample, but not limited to” or “such as, but not limited to” andencompasses other similar or equivalent examples.

Suppliers of commercially available starting materials include thefollowing. Dow Silicones Corporation means Dow Silicones Corporation ofMidland, Mich., US. Gelest means Gelest, Inc. of Morrisville, Pa., USA.Millipore Sigma is (Sigma-Aldrich) of St. Louis, Mo., USA.

Generally, as used herein a hyphen “-” or dash “-” in a range of valuesis “to” or “through”; a “>” is “above” or “greater-than”; a “≥” is “atleast” or “greater-than or equal to”; a “<” is “below” or “less-than”;and a “≤” is “at most” or “less-than or equal to.” On an individualbasis, each of the aforementioned applications for patent, patents,and/or patent application publications, is expressly incorporated hereinby reference in its entirety in one or more non-limiting embodiments.

It is to be understood that the appended claims are not limited toexpress and particular compounds, compositions, or methods described inthe detailed description, which may vary between particular embodimentswhich fall within the scope of the appended claims.

Alternative Embodiments of the Invention

In a first embodiment, a method for preparing a product comprises:

1) combining starting materials comprisingA) a boron containing Lewis acid;B) a hydroxyl terminated polydiorganosiloxane of formula

where each subscript n is 2 to 2,000, and each R¹ is independentlyselected from the group consisting of monovalent hydrocarbon groups andmonovalent halogenated hydrocarbon groups; andC) a cyclic polyorganohydrogensiloxane of formula (RHSiO_(2/2))_(v),where subscript v is 3 to 12; and each R is an independently selectedmonovalent hydrocarbon group; thereby preparing the product comprising apolyfunctional organohydrogensiloxane and a by-product comprising H₂.

In a second embodiment, the method of the first embodiment furthercomprises one or more additional steps selected from the groupconsisting of:

during and/or after step 1), removing the H₂ generated during formationof the polyfunctional organohydrogensiloxane; and/or

neutralizing residual boron containing Lewis acid in the product and/orremoving a by-product, and/or

recovering the polyfunctional organohydrogensiloxane.

In a third embodiment, the A) boron containing Lewis acid is a trivalentboron compound with at least one perfluoroaryl group.

In a fourth embodiment, subscript n is 2 to 1,000, and each R¹ isselected from the group consisting of an alkyl group of 1 to 20 carbonatoms, an alkenyl group of 2 to 20 carbon atoms, an aryl group of 6 to20 carbon atoms, or a halogenated alkyl group of 1 to 20 carbon atoms.

In a fifth embodiment, subscript v is 4 to 10, and each R is an alkylgroup of 1 to 6 carbon atoms.

A sixth embodiment relates to the product comprising the polyfunctionalorganohydrogensiloxane prepared by the method of any one of the first tofifth embodiments.

In a seventh embodiment, the product comprises a polyfunctionalorganohydrogensiloxane of unit formula:[(HRSiO_(2/2))_(v-1)(—RSiO_(2/2))]₂[O—(R¹₂SiO_(2/2))_(n)]_(n′)[(HRSiO_(2/2))_(v-2)(—RSiO_(2/2))₂]_(o′,) whereeach subscript n is independently 2 to 2,000, each subscript v isindependently 3 to 12; subscript o′ is 0 to 100, subscript n′=(o′+1),and each R is an independently selected monovalent hydrocarbon group,and each R¹ is independently selected from the group consisting ofmonovalent hydrocarbon groups and monovalent halogenated hydrocarbongroups.

In an eighth embodiment, the product comprises a polyfunctionalorganohydrogensiloxane of formula:

In a ninth embodiment, a method for preparing a release coatingcomposition comprises combining starting materials comprising: (i) theproduct of the sixth embodiment or the polyfunctionalorganohydrogensiloxane of the seventh embodiment or the eighthembodiment;

(ii) a polyorganosiloxane having an average, per molecule, of at leasttwo silicon bonded aliphatically unsaturated groups capable ofundergoing hydrosilylation reaction,(iii) a hydrosilylation reaction catalyst, and(iv) a hydrosilylation reaction inhibitor.

In a tenth embodiment, the method further comprises adding to therelease coating composition one or more additional starting materialsselected from the group consisting of: (v) an anchorage additive, (vi)an anti-mist additive, (vii) a controlled release agent, (viii) a linearpolyorganohydrogensiloxane, and (ix) a solvent.

In an eleventh embodiment, in the method of the ninth or tenthembodiment, starting material (ii) comprises a polyorganosiloxane ofunit formula: (R¹⁰R⁹ ₂SiO_(1/2))_(aa)(R¹⁰R⁹SiO_(2/2))_(bb)(R¹⁰₂SiO_(2/2))_(cc)(R⁹ ₃SiO_(1/2))_(dd), where each R⁹ is an independentlyselected monovalent hydrocarbon group that is free of aliphaticunsaturation or a monovalent halogenated hydrocarbon group that is freeof aliphatic unsaturation; each R¹⁰ is independently selected from thegroup consisting of alkenyl and alkynyl; subscript aa is 0, 1, or 2,subscript bb is 0 or more, subscript cc is 1 or more, subscript dd is 0,1, or 2, with the provisos that a quantity (aa+bb) 2, and (aa+dd)=2,with the proviso that a quantity (aa+bb+cc+dd) is 3 to 2,000.

In a twelfth embodiment, in the method of the eleventh embodiment,starting material (ii) comprises a substantially linear, alternativelylinear, polyorganosiloxane selected from the group consisting of:

i) dimethylvinylsiloxy-terminated polydimethylsiloxane,ii) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylvinylsiloxane),iii) dimethylvinylsiloxy-terminated polymethylvinylsiloxane,iv) trimethylsiloxy-terminatedpoly(dimethylsiloxane/methylvinylsiloxane),v) trimethylsiloxy-terminated polymethylvinylsiloxane,vi) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylvinylsiloxane),vii) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylphenylsiloxane),viii) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/diphenylsiloxane),ix) phenyl,methyl,vinyl-siloxy-terminated polydimethylsiloxane,x) dimethylhexenylsiloxy-terminated polydimethylsiloxane,xi) dimethylhexenylsiloxy-terminatedpoly(dimethylsiloxane/methylhexenylsiloxane),xii) dimethylhexenylsiloxy-terminated polymethylhexenylsiloxane,xiii) trimethylsiloxy-terminatedpoly(dimethylsiloxane/methylhexenylsiloxane),xiv) trimethylsiloxy-terminated polymethylhexenylsiloxanexv) dimethylhexenyl-siloxy terminatedpoly(dimethylsiloxane/methylhexenylsiloxane),xvi) dimethylvinylsiloxy-terminatedpoly(dimethylsiloxane/methylhexenylsiloxane), andxvii) a combination thereof.

In a thirteenth embodiment, in the method of any one of the ninth totwelfth embodiments, starting material (ii) comprises a branchedsiloxane of formula:

where subscript u is 0 or 1, each subscript t is independently 0 to 995,alternatively 15 to 995, each R¹¹ is an independently selectedmonovalent hydrocarbon group, each R⁹ is an independently selectedmonovalent hydrocarbon group that is free of aliphatic unsaturation or amonovalent halogenated hydrocarbon group that is free of aliphaticunsaturation as described above, and each R¹⁰ is independently selectedfrom the group consisting of alkenyl and alkynyl as described above.

In a fourteenth embodiment, in the method of any one of the ninth tothirteenth embodiments, the hydrosilylation reaction catalyst isselected from the group consisting of Karstedt's catalyst and Ashby'scatalyst.

In a fifteenth embodiment, in the method of any one of the ninth tofourteenth embodiments, the hydrosilylation reaction inhibitor isselected from the group consisting of acetylenic alcohols (e.g.,1-ethynyl-1-cyclohexanol) and maleates (e.g., diallyl maleate, bismaleate, or n-propyl maleate), and a combination of two or more thereof.

In a sixteenth embodiment, in the method of any one of the tenth tofifteenth embodiments the anchorage additive is present and comprises apolyorganosilicate resin.

In a seventeenth embodiment, in the method of any one of the tenth tosixteenth embodiments, the substantially linear or linearpolyorganohydrogensiloxane is present and comprises unit formula: (HR¹²₂SiO_(1/2))_(v′)(HR¹²SiO_(2/2))_(w′)(R¹² ₂SiO_(2/2))_(x′)(R¹²₃SiO_(1/2))_(y′), where each R¹² is an independently selected monovalenthydrocarbon group, subscript v′ is 0, 1, or 2, subscript w′ is 1 ormore, subscript x′ is 0 or more, subscript y′ is 0, 1, or 2, with theprovisos that a quantity (v′+y′)=2, and a quantity (v′+w′)≥3, and aquantity (v′+w′+x′+y′) is 2 to 1,000.

In an eighteenth embodiment, in the method of the seventeenthembodiment, the polyorganohydrogensiloxane is selected from the groupconsisting of:

i) dimethylhydrogensiloxy-terminatedpoly(dimethyl/methylhydrogen)siloxane copolymer,ii) dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane,iii) trimethylsiloxy-terminated poly(dimethyl/methylhydrogen)siloxanecopolymer,iv) trimethylsiloxy-terminated polymethylhydrogensiloxane, andv) two or more of i) to iv).

In a nineteenth embodiment, a method for preparing a clusteredfunctional organosiloxane comprises:

1) combining starting materials comprisinga) the product prepared by the method of any one of the first to sixthembodiments or the polyfunctional organohydrogensiloxane of the seventhor eighth embodiments,b) a hydrosilylation reaction catalyst, andc) a reactive species having an average, per molecule at least onealiphatically unsaturated group capable of undergoing an additionreaction with a silicon bonded hydrogen atom of starting material a) andfurther comprising one or more curable groups per molecule; therebypreparing a product comprising the clustered functional organosiloxane.

In a twentieth embodiment, a method for preparing an adhesivecomposition comprises 1) combining starting materials comprising

A) the product or the clustered functional organosiloxane of thenineteenth embodiment;

B) a reactive resin and polymer,

C) a condensation reaction catalyst, and

D) a free radical initiator.

In a twenty-first embodiment, in the method of the nineteenth ortwentieth embodiments, the clustered functional organosiloxane has unitformula: [(R⁸RSiO_(2/2))_(v-1)(—RSiO_(2/2))]₂[O—(R¹₂SiO_(2/2))_(n)]_(n′)[(R⁸RSiO_(2/2))_(v-2)(—RSiO_(2/2))₂]_(o′), whereeach subscript n is independently 2 to 2,000, each subscript v isindependently 3 to 12; subscript o′ is 0 to 100, subscript n′=(o′+1),and each R is an independently selected monovalent hydrocarbon group,each R¹ is independently selected from the group consisting ofmonovalent hydrocarbon groups and monovalent halogenated hydrocarbongroups, each R⁸ is independently selected from the group consisting of Hand curable groups, with the proviso that at least one R⁸ per moleculeis a curable group (other than H).

In a twenty-second embodiment, product comprises a clustered functionalorganosiloxane of formula:

formula

where each subscript n is independently 2 to 2,000, each subscript v isindependently 3 to 12; each R is an independently selected monovalenthydrocarbon group, each R¹ is independently selected from the groupconsisting of monovalent hydrocarbon groups and monovalent halogenatedhydrocarbon groups, each R⁸ is independently selected from the groupconsisting of H and curable groups, with the proviso that at least oneR⁸ per molecule is a curable group (other than H).

In a twenty-third embodiment, the curable group in the twenty-first ortwenty-second embodiment is selected from the group consisting oforganic groups containing epoxy, acrylate, or methacrylatefunctionality.

In a twenty-fourth embodiment, method of any one of the twentieth totwenty-third embodiments, starting material B) is a poly-alkoxyendblocked resin-polymer blend comprising a reaction product of

i) a siloxane resin comprising units of formulae (R^(2′) ₃SiO_(1/2)) and(SiO_(4/2)), where each R^(2′) is independently a monovalent hydrocarbongroup, with the proviso that at least one R^(2′) per molecule hasaliphatic unsaturation, wherein the siloxane resin has a molar ratio of(R^(2′) ₃SiO_(1/2)) units (M units) to (SiO_(4/2)) units (Q units)ranging from 0.5:1 to 1.5:1 (M:Q ratio),

ii) a polydiorganosiloxane comprising units of formulae (R^(2′)₃SiO_(1/2))_(ii) and (R₂SiO_(2/2))_(hh) (D units), where subscript hh is20 to 1000 and subscript ii has an average value of 2, and

iii) an alkoxy-functional organohydrogensiloxane oligomer. Thealkoxy-functional organohydrogensiloxane oligomer has unit formula

(HR²² ₂SiO_(1/2))_(ppp)(R²² ₃SiO_(1/2))_(qqq)(HR²²SiO_(2/2))_(rrr) (R²²₂SiO_(2/2))_(sss)(R²²SiO_(3/2))_(ttt)(HSiO_(3/2))_(uuu)(SiO_(4/2))_(kk),where each D¹ independently represents a divalent hydrocarbon group of 2to 18 carbon atoms; each R²² independently represents a monovalenthydrocarbon group of 1 to 18 carbon atoms or a monovalent halogenatedhydrocarbon group of 1 to 18 carbon atoms (such as those described abovefor R¹), each R²³ is independently a monovalent hydrocarbon group of 1to 18 carbon atoms (such as those described above for R¹), subscript nnnis 0 or 1, subscript 000 is 0, subscripts qqq, sss, and ttt have valuessuch that 5≥qqq≥0, 5≥sss≥0, subscript ttt is 0 or 1, subscript kk is 0or 1, subscript nnn>0, and a quantity(mmm+ppp+qqq+rrr+sss+ttt+uuu+kk)≤50, with the proviso that >90 mol % ofall D¹ groups in the endblocker are linear; and

iv) a hydrosilylation reaction catalyst.

In a twenty-fifth embodiment, method of any one of the twentieth totwenty-fourth embodiments, starting material C) is selected from thegroup consisting of: a) stannic salts of carboxylic acids, b) tin (II)salts of organic carboxylic acids, c) stannous salts of carboxylic acidsd) organotitanium compounds, and e) combinations of two or more of a),b), c), and d) organotitanium compounds.

In a twenty-sixth embodiment, method of any one of the twentieth totwenty-fifth embodiments, starting material D) is selected from thegroup consisting of azo compounds and organic peroxide compounds.

In a twenty-seventh embodiment, method of any one of the twentieth totwenty-sixth embodiments, the adhesive composition further comprises anadditional starting material selected from the group consisting of E) adual cure compound, F) an adhesion promoter, G) a corrosion inhibitor,H) a rheology modifier, I) a drying agent, J) a crosslinker, K) afiller, L) a spacer, M) an acid scavenger, N) a silanol functionalpolydiorganosiloxane, O) a fluorescent optical brightener, P) a chaintransfer agent, Q) a (meth)acrylate monomer, R) a poly-alkoxy terminatedpolydiorganosiloxane, S) a colorant, and two or more of E), F), G), H),I), J), K), L), M), N), O), P), Q), R), and S).

In a twenty-eighth embodiment, in the method of the twenty-seventhembodiment the E) dual cure compound is present, and the dual curecompound is selected from the group consisting ofmethacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane,acryloxypropyltriethoxysilane, methacryloxypropyltriethoxysilane,methacryloxypropylmethyldimethoxysilane,acryloxypropylmethyldimethoxysilane,acryloxypropyldimethylmethoxysilane,methacryloxypropyldimethylmethoxysilane, and a combination of two ormore thereof.

In a twenty-ninth embodiment, in the method of the twenty-seventh or thetwenty-eighth embodiment, the F) adhesion promoter is present, and theadhesion promoter is selected from the group consisting ofbeta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, triallylisocyanurate, trimethoxysilylterminated polydimethylsiloxane, and a combination of two or morethereof.

In a thirtieth embodiment, in the method of any one of thetwenty-seventh to twenty-ninth embodiments, the G) corrosion inhibitoris present, and the corrosion inhibitor is selected from the groupconsisting of 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole,mercaptabenzotriazole, alkylthiadiazole and a combination of two or morethereof.

In a thirty-first embodiment, in the method of any one of the twentiethto thirtieth embodiments, the adhesive composition further comprises analkoxysilane.

In an thirty-second embodiment, the alkoxysilane is selected from thegroup consisting of vinyltrimethoxysilane, vinyltriethoxysilane,methyltrimethoxysilane, isobutyltrimethoxysilane, and a combination oftwo or more thereof.

In a thirty-third embodiment, in the method of any one of thetwenty-seventh to thirty-first embodiments, the K) filler is present,and the filler comprises fume silica.

In a thirty-fourth embodiment, in the method of any one of thetwenty-seventh to thirty-first embodiments, the L) spacer is present,and the spacer comprises glass beads.

1. A method for preparing a product comprising: 1) combining startingmaterials comprising A) a boron containing Lewis acid; B) a hydroxylterminated polydiorganosiloxane of formula

where subscript n is 2 to 2,000, and each R¹ is independently selectedfrom the group consisting of monovalent hydrocarbon groups andmonovalent halogenated hydrocarbon groups; and C) a cyclicpolyorganohydrogensiloxane of formula (RHSiO_(2/2))_(v), where subscriptv is 3 to 12; and each R is an independently selected monovalenthydrocarbon group; thereby preparing the product comprising apolyfunctional organohydrogensiloxane and a by-product comprising H₂;and 2) combining a) the polyfunctional organohydrogensiloxane, b) ahydrosilylation reaction catalyst, and c) a reactive species having anaverage, per molecule at least one aliphatically unsaturated groupcapable of undergoing an addition reaction with a silicon bondedhydrogen atom of starting material a) and further comprising one or morecurable groups per molecule.
 2. The method claim 1, where the A) boroncontaining Lewis acid is a trivalent boron compound with at least oneperfluoroaryl group.
 3. The method claim 1, where subscript n is 2 to1,000, subscript v is 4 to 10, each R is an alkyl group of 1 to 6 carbonatoms, and each R¹ is selected from the group consisting of an alkylgroup of 1 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms,an aryl group of 6 to 20 carbon atoms, or a halogenated alkyl group of 1to 20 carbon atoms.
 4. The method of claim 1, further comprising: 2)during and/or after step 1), removing the H₂ generated during formationof the polyfunctional organohydrogensiloxane.
 5. The method of claim 1,further comprising: 3) neutralizing residual boron containing Lewis acidin the polyfunctional organohydrogensiloxane.
 6. (canceled)
 7. Themethod of claim 16, where the reactive species comprises a silane offormula R⁴ _(y)SiR⁵ _((4-y)), where subscript y is 1 to 3, each R⁴ isthe aliphatically unsaturated group capable of undergoing an additionreaction, and each R⁵ is the curable group; thereby preparing a productcomprising a clustered functional organosiloxane.
 8. The method of claim16, where the reactive species has formula R⁶R⁷, where each R⁶ is thealiphatically unsaturated group capable of undergoing an additionreaction, and each R⁷ is the curable group.
 9. A product prepared by themethod of claim
 17. 10. The product of claim 9, where the productcomprises a polyfunctional organohydrogensiloxane of unit formula:[(HRSiO_(2/2))_(v-1)(—RSiO_(2/2))]₂[O—(R¹₂SiO_(2/2))_(n)]_(n′)[(HRSiO_(2/2))_(v-2)(—RSiO_(2/2))₂]_(o′), wheresubscript o′ is 0 to 100 and subscript n′=(o′+1).
 11. The product ofclaim 10, where subscript o′=0, and the polyfunctionalorganohydrogensiloxane has formula:


12. (canceled)
 13. A product prepared by the method of claim
 1. 14. Theproduct of claim 13, where the product comprises a clustered functionalorganopolysiloxane of unit formula:[(R⁸RSiO_(2/2))_(v-1)(—RSiO_(2/2))]₂[O—(R¹₂SiO_(2/2))_(n)]_(n′)[(R⁸RSiO_(2/2))_(v-2)(—RSi)_(2/2))₂]_(o′), whereeach subscript o′ is 0 to 100, subscript n′=(o′+1), and each R⁸ isindependently selected from the group consisting of H and a curablegroup, with the proviso that at least one R⁸ per molecule is the curablegroup (other than H).
 15. The product of claim 14, where subscript o′=0and the product comprises a clustered functional organopolysiloxane offormula:


16. (canceled)
 17. A curable composition comprising: (I) the product ofclaim 13, and (II) a curing agent.
 18. A method for preparing a productcomprising: 1) combining starting materials comprising A) a boroncontaining Lewis acid; B) a hydroxyl terminated polydiorganosiloxane offormula

where subscript n is 2 to 2,000, and each R¹ is independently selectedfrom the group consisting of monovalent hydrocarbon groups andmonovalent halogenated hydrocarbon groups; and C) a cyclicpolyorganohydrogensiloxane of formula (RHSiO_(2/2))_(v), where subscriptv is 3 to 12; and each R is an independently selected monovalenthydrocarbon group; thereby preparing the product comprising apolyfunctional organohydrogensiloxane and a by-product comprising H₂,wherein B) the hydroxyl terminated polydiorganosiloxane and C) thecyclic polyorganohydrogensiloxane are used in amounts such that SiH:SiOHratio is 4:1 to 40:1.
 19. The method claim 18, where the A) boroncontaining Lewis acid is a trivalent boron compound with at least oneperfluoroaryl group.
 20. The method claim 18, where subscript n is 2 to1,000, subscript v is 4 to 10, each R is an alkyl group of 1 to 6 carbonatoms, and each R¹ is selected from the group consisting of an alkylgroup of 1 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms,an aryl group of 6 to 20 carbon atoms, or a halogenated alkyl group of 1to 20 carbon atoms.
 21. The method of claim 18, further comprising: 2)during and/or after step 1), removing the H₂ generated during formationof the polyfunctional organohydrogensiloxane.
 22. The method of claim18, further comprising: 3) neutralizing residual boron containing Lewisacid in the polyfunctional organohydrogensiloxane.
 23. A curablecomposition comprising: (I) the product of claim 9, and (II) a curingagent.